I’m evidently behind the times, but autonomous quadcopters are apparently quite the rage in University robotics research these days. The quadcopters in the following videos were designed and programmed by the GRASP Laboratory at the University of Pennsylvania and the Flying Machine Arena at ETH Zürich. According to Wikipedia, MIT’s Aerospace Controls Lab has also engaged in similar research.

If you like these, hit the link at the bottom of this post for more information and more videos from the Flying Machine Arena at ETH Zurich.

More info and videos at the Flying Machine Arena website ›

Like a vain woman

John Piper on C. S. Lewis on praise:

Lewis says that as he was beginning to believe in God, a great stumbling block was the presence of demands scattered through the Psalms that he should praise God. He did not see the point in all this; besides, it seemed to picture God as craving “for our worship like a vain woman who wants compliments.” He goes on to show why he was wrong:

“But the most obvious fact about praise—whether of God or anything—strangely escaped me. I thought of it in terms of compliment, approval, or the giving of honor. I had never noticed that all enjoyment spontaneously overflows into praise. . . . The world rings with praise—lovers praising their mistresses, readers their favorite poet, walkers praising the countryside, players praising their favorite game. . . .

“My whole, more general difficulty about the praise of God depended on my absurdly denying to us, as regards the supremely Valuable, what we delight to do, what indeed we can’t help doing, about everything else we value.

“I think we delight to praise what we enjoy because the praise not merely expresses but completes the enjoyment; it is its appointed consummation.”12

  1. C. S. Lewis (1958). Reflections on the Psalms (pp. 94–95). Harcourt, Brace & World. []
  2. Piper, John (2011). Desiring God, Revised Edition: Meditations of a Christian Hedonist (Kindle Locations 253–264). Random House, Inc. Kindle Edition. []

Sins of ignorance

J. C. Ryle on sins committed in ignorance:

But I do think it necessary in these times to remind my readers that a man may commit sin and yet be ignorant of it and fancy himself innocent when he is guilty. I fail to see any scriptural warrant for the modern assertion that: ‘Sin is not sin to us until we discern it and are conscious of it.’ On the contrary, in the fourth and fifth chapters of that unduly neglected book, Leviticus, and in the fifteenth of Numbers, I find Israel distinctly taught that there were sins of ignorance which rendered people unclean and needed atonement (Leviticus 4:1–35; 5:14–19; Numbers 15:25–29). And I find our Lord expressly teaching that ‘the servant who knew not his master’s will and did it not’, was not excused on account of his ignorance, but was ‘beaten’ or punished (Luke 12:48). We shall do well to remember that, when we make our own miserably imperfect knowledge and consciousness the measure of our sinfulness, we are on very dangerous ground. A deeper study of Leviticus might do us much good.1

  1. Ryle, J. C. (1952). Holiness (Kindle Locations 331-338). Heritage Bible Fellowship. Kindle Edition. []


The university I work for, Western Governors University, is celebrating fifteen years this year, and it just occurred to me I’ve been around for nearly half those years (the last seven). It started out a pretty amazing idea by some pretty amazing people, turned out to be a pretty amazing university, and I consider it a pretty amazing place to work. Happy birthday, WGU!


My wife wrote a lovely happy birthday message to our recently-turned-two-year-old this week, and toward the end she remarked, “I am curious what your daddy would add to this list…” So here I am adding to her list.

Happy birthday, E. You have no idea how much you are worried about, gushed and cooed over, and just flat out loved by Mom and Dad (not to mention your two Grandmas, Opa, Grandfather, and a gaggle of aunts, uncles and cousins).

Following Mom’s lead, here are some things you do that make me smile:

  • You’re finally taking my advice and learning English. (And if I ask you what language you’re learning, you answer, “English”.)
  • Even though you can’t read, you know what all your shirts say because we tell you and you remember. I showed you this picture yesterday and asked you what your shirt says, and you said, “I’s love Dad”:
    E wearing his “I ♥ MY DAD” shirt
  • You call Smarties “Farties”. (See mom’s recent post and video about this.)
  • You are starting to figure out subjects, objects and indirect objects, but you get them in the wrong order sometimes. The other day you said to mom, “Mom [subject] get Dad [indirect object] a car [direct object],” which was phenomenal, but you will sometimes say things like, “E pick Dad up,” when you really mean “Dad pick E up.” I’ve offered to help you diagram that sentence, but you oddly don’t seem interested in that. You’ll figure this stuff out, I’m sure, and in the meantime it’s genuinely fun seeing the wheels turning in your head as you experiment with language.
  • You love driving the train with me (the Toca Train app on my iPhone/iPad). We have lots of fun together picking up passengers and loading things on and off our flatbed car with the crane.
  • You also like playing Legos with me (Duplo Legos), but the fun is definitely not in helping me build something, but rather in destroying whatever it is I’m trying to build. Don’t get me wrong, I’m not at all upset by this, but I do look forward to a time when we will have more fun building things together.
  • Ever since Aunt Kathlene got her new kitten, Gracie, when we sing “Amazing Grace” you won’t sing the actual words, but instead want to insert “Gracie” into every line. (“Amazing Gracie! How sweet the Gracie. That saved a Gracie like Gracie!”)
  • You are an amazing eater. You’ll eat anything we put on your plate. We’ve fed you every variety of salsa (from mild all the way up to hot) and you seem to have no problem with any of them. I fed you some jalapeño jelly the other day and you loved it. You’ve enjoyed octopus, sushi, fresh lemon, avocado (guacamole), coffee, and many foods I turn my nose up to, like mushrooms and various other vegetables and fruits. There are one or two things you turn your nose up at, but for the most part you eat anything put before you in a seeming state of ignorant bliss. Everything is new, and therefore, everything is worth trying.

Well, my list isn’t as long as your mom’s, but right now I’m faced with the choice of either adding more things to this list or sitting down to play with you, and I’d like the record to show that I made the right choice right now. I love you to pieces, kiddo. 

On consistency between Biblical authors

I was explaining to my wife the other night that whenever I encounter a difficult passage in the Bible, I try to look for related information from the same writer. I don’t immediately jump over to passages in other books of the Bible, pitting one passage against another and letting them duke it out to see who wins. This kind of Bible bashing is, in my opinion, a fundamentally flawed approach and should not be employed by anyone who holds to the principles of perspicuity and inerrancy of God’s word. Instead, I try to understand the difficult passage in its own context, and by context I mean moving in concentric circles from the paragraph to the chapter to the book and then finally to other books by the same writer.

In our brief discussion, my wife agreed with me about context being important, but she found it curious that I would say that I look at statements by the same author and try to avoid other authors until I have a greater understanding of what that one author really meant. I’ve been approaching scripture this way for a while almost without thinking about it and without ever expressing or explaining it to anyone else, and her curiosity about it set in motion some introspection and self-reflection about why I do it. These comments are an attempt to set into words my thought process.

Why do I stay within single authors?

From the world’s perspective, the Bible was written by several individual men. From a Christian worldview, the various scripture books all had one author, namely God, notwithstanding they were written as God inspired those individual men.

If it can be shown that any Biblical author contradicts himself (is not internally consistent within his own writings) then we have really serious problems. Either (1) that author was of lesser intelligence and incapable of articulating cogent and consistent arguments or (2) that author was insane and actually concurrently believed contradictory truth claims, (3) that author changed his mind at some time or (4) at least some or all the documents claimed to be by that author are of dubious authorship and were therefore mistakenly included among the canon.

If it can be shown that the several Biblical authors are each internally consistent, but that they contradict each other, then we can conclude the Bible was written by intelligent but uninspired men who held to cogent and consistent but nevertheless contradictory and competing worldviews. It then becomes a contest as to which one of these authors’ systems of theology is inspired (and thus true) and which are wrong, or if they are all wrong together.

If it can be shown that each Biblical author is internally consistent and is furthermore externally consistent with all other Biblical authors, in other words, that the Bible taken as a whole is internally consistent, then that is possible cause for believing that God authored the scriptures. Considered another way, a necessary condition (but not a sufficient condition) for accepting the Bible as God-inspired is being able to show that the whole Bible is internally consistent.

It is in consideration of the above three “ifs” (the above three paragraphs) that I pay very careful attention to the various authors to make sure they are consistent within their own writings and also with the other authors. If one passage in the Bible seems to contradict the rest of the Bible theologically, I first look for instances from the same author where he is consistent with the rest of the scriptures. Then I consider why he may seem to be contradicting himself in the one passage in question. I try to consider that one author in a vacuum and interact with only his writings before I begin to look outside his writings.

Some working examples

So, for instance, when I look at a difficult passage for perseverance of the saints like Hebrews 6:4-6, I don’t immediately jump over to the best related verses by other authors in other books of the Bible (like John 6:37-40 or John 10:28-29), but I stay right where I am and notice Hebrews 6:9-12, where the author clarifies what he really meant in Hebrews 6:4-6 by stating that, “though we speak in this way,” he is confident that his audience won’t really fall away from faith. Moving further out, but staying with the same author1, I find Hebrews 7:25; Hebrews 10:14; Hebrews 10:36-39; Hebrews 12:2 and Hebrews 13:5. Clearly the author of Hebrews positively affirms the doctrine of perseverance of the saints.

Another good example is a difficult passage for limited atonement, 1 John 2:2. Compare and contrast that to the almost word-for-word passage John 11:51-52. The parallel statement by the same author helps to clarify the author’s intended meaning. Additionally, passages like John 6:38-39; John 10:11; John 10:14-16; John 13:1; John 15:13; John 17:1-2, 9; 1 John 3:16 and Revelation 5:9 help to establish that John did indeed hold to the doctrine of limited atonement.

Not just for difficult passages

I should mention that this doesn’t apply only to difficult passages. For instance, as John Piper recently pointed out2, 1 and 2 John are the best commentary you’ll ever find on Jesus’ new commandment in John 13:34-35.

A corollary to this whole idea is not only looking for consistency within authors but looking for consensus among several authors. For instance, in Sunday School at Jordan Presbyterian Church this morning, Pastor Reid found evidence for the historicity of the universal deluge by surveying various Old and New Testament authors. The author of 1 Chronicles includes Noah in Abraham’s genealogy (1 Chronicles 1:4) and Luke includes him in Jesus’ genealogy (Luke 3:36), so they both evidently believed Noah was a real person. Furthermore, Isaiah, Jesus (attested by both Matthew and Luke), the author of Hebrews and Peter all treat the flood as though it was a real historical event (See Isaiah 54:9; Matthew 24:37-39; Luke 17:26-27; Hebrews 11:7; 1 Peter 3:20 and 1 Peter 2:5). Whether you realize it or not, if you allegorize the flood then you are calling into question the credibility of all these Biblical figures.


So I hope I’ve helped you see why paying attention to authorship is a huge part of my hermeneutic—my way of learning from and interpreting the Bible. Realizing how the Old Testament prophecies of Jesus are so amazingly fulfilled in the New Testament was one of the things that made me recognize the authenticity of the Bible in the first place. Realizing further that the Bible was written by multiple authors and yet they are all consistent in what they believed and taught has really helped to solidify that belief for me. I hope I’ve encouraged you to look at the Bible in a different way as you consider the various authors and how they support each other. 

Photo credit: le vent le cri.

  1. It may be important to note here that the writer of Hebrews is anonymous. Hebrews was widely attributed to Paul in the early centuries of Christendom, but in recent years faithful Christians have questioned authorship since the epistle doesn’t contain Paul’s usual greeting and benediction, and has a markedly different style. Some have speculated that Barnabas, Luke, Apollos or Priscilla wrote the book, but ultimately we are left with an unknown. So, to consider writings by the author of Hebrews, I could look to the other writings of Luke if I had any reason to feel confident about that possibility, but ultimately I’m forced to stay within the book of Hebrews. []
  2. See Piper’s sermon, As I Have Loved You, Love One Another, from March 17, 2012. []