Thinking as pruning, shaking together, weighing, imagining

I am wearing a wonderful t-shirt today, created for me by Gili Rusak, an awesome alumna in our math circle. I am wearing a wonderful t-shirt today, created by a math circle alumna Gili Rusak for me last year.

Descartes famously wrote "I think, therefore I am." Of course, he wrote it in French (his native language) and later rewrote it in Latin (the language of scholarship at the time), rather than in English. And Latin has two distinct verbs, "cogito" and "puto" that both translate into our single English phrase "I think." The two Latin words connote very different ideas of what it means to think.

The etymology of the word cogito literally means "I shake together."  The root word is related to our English word agitate.  So we could illustrate this with a Descartes shaking ideas together with a cocktail shaker.

Although Descartes actually chose cogito, my favorite image of thinking is actually associated with the alternative word puto, because it derives from a root word meaning "I prune."  Thinking involves a lot of pruning, of cutting away clutter.  I love the image of Descartes with pruning shears.

But before he wrote in Latin, what he actually wrote in French was "Je pense, donc je suis."  The etymology of the French verb penser has nothing to do with either shaking or pruning.  It derives from a word that means to weigh or balance.  So we could illustrate  that with Descartes holding a balance scale with competing ideas piled up on either side.

He didn't write in English, of course, but it is also interesting to consider the etymology of the English verb think.  From the Online Etymology dictionary, we have:

think (v.) Old English þencan "imagine, conceive in the mind; consider, meditate, remember; intend, wish, desire" (past tense þohte, past participle geþoht), probably originally "cause to appear to oneself," from Proto-Germanic *thankjan (source also of Old Frisian thinka, Old Saxon thenkian, Old High German denchen, German denken, Old Norse þekkja, Gothic þagkjan).

Our ability to think is an amazing and multifaceted superpower to reflect upon.  We need to shake ideas together, to prune and simplify, to weigh ideas against one another, and to imagine and conceive.