An everyday example of this temporal illusion is seen in high-speed sports such as baseball and tennis. Though batters sense that they withhold deciding whether to swing until they see the ball near the plate, their swing actually begins shortly after the ball leaves the pitcher’s hand. The same applies to tennis players returning a serve coming at them at 140 miles an hour. Initiation of the action precedes full conscious perception of seeing the approaching ball.

It is unlikely that there is any fundamental difference in how the brain initiates thought and action. We learn the process of thinking incrementally, acquiring knowledge of language, logic, the external world and cultural norms and expectations just as we learn physical actions like talking, walking or playing the piano. If we conceptualize thought as a mental motor skill subject to the same temporal reorganization as high-speed sports, it’s hard to avoid the conclusion that the experience of free will (agency) and conscious rational deliberation are both biologically generated illusions.

What then are we to do with the concept of rationality? It would be a shame to get rid of a term useful in characterizing the clarity of a line of reasoning. Everyone understands that “being rational” implies trying to strip away biases and innate subjectivity in order to make the best possible decision. But what if the word rational leads us to scientifically unsound conclusions?

We describe the decision to jam on the brakes at the sight of a child running into the road as being rational, even when we understand that it is reflexive. However, few of us would say that a self-driving car performing the same maneuver was acting rationally. It’s pretty obvious that the difference in how we assign rationality isn’t dependent upon how decisions are made, but how we wish to see ourselves in relationship to the rest of the animal kingdom, and indeed even to plants and intelligent machines.

It is hard to imagine what would happen to modern thought if we abandoned the notion of rationality. Scientific method might partly fill the void. With quantum physics, scientists have been able to validate counterintuitive theories. But empirical methods can’t help us with abstract, non-measurable, linguistically ambiguous concepts such as purpose and meaning. It’s no wonder that pre-eminent scientists like Stephen Hawking have gleefully declared, “Philosophy is dead.”

Going forward, the greatest challenge for philosophy will be to remain relevant while conceding that, like the rest of the animal kingdom, we are decision-making organisms rather than rational agents, and that our most logical conclusions about moral and ethical values can’t be scientifically verified nor guaranteed to pass the test of time. (The history of science should serve as a cautionary tale for anyone tempted to believe in the persistent truth of untestable ideas).

Even so, I would hate to discard such truisms such as “know thyself” or “the unexamined life isn’t worth living.” Reason allows us new ways of seeing, just as close listening to a piece of music can reveal previously unheard melodies and rhythms or observing an ant hill can give us an unexpected appreciation of nature’s harmonies. These various forms of inquiry aren’t dependent upon logic and verification; they are modes of perception.