Even his simplest perceptions cannot be relied upon. If he has a fever or has taken medicine, everything tastes different or appears with different colors. A mild cold befuddles the mind; dementia would knock it out entirely. Socrates himself could be rendered a vacant idiot by a stroke or brain damage, and if a rabid dog bit him, he would talk nonsense. The dog’s saliva could make “all philosophy, if it were incarnate, raving mad.” And this is just the point: for Montaigne, philosophy is incarnate. It lives in individual, fallible humans; therefore, it is riddled with uncertainty. “The philosophers, it seems to me, have hardly touched this chord.”
And what of the perceptions of different species? Montaigne correctly guesses (as Sextus did before him) that other animals see colors differently from humans. Perhaps it is we, not they, who see them “wrongly.” We have no way of knowing what the colors really are. Animals have faculties that are weak or lacking in us, and maybe some of these are essential to a full understanding of the world. “We have formed a truth by the consultation and concurrence of our five senses; but perhaps we needed the agreement of eight or ten senses, and their contribution, to perceive it certainly and in its essence.”
This seemingly casual remark proposes a shocking idea: that we may be cut off by our very nature from seeing things as they are. A human being’s perspective may not merely be prone to occasional error, but limited by definition, in exactly the way we normally (and arrogantly) presume a dog's intelligence to be. Only someone with an exceptional ability to escape his immediate point of view could entertain such an idea, and this was precisely Montaigne’s talent: being able to slip out from behind his eyes so as to gaze back upon himself with Pyrrhonian suspension of judgment. Even the original Skeptics never went so far. They doubted everything around them, but they did not usually consider how implicated their innermost souls were in the general uncertainty. Montaigne did, all the time.
We, and our judgment, and all mortal things go on flowing and rolling unceasingly. Thus nothing certain can be established about one thing by another, both the judging and the judged being in continual change and motion.
This might seem a dead end, closing off all possibility of knowing anything, since nothing can be measured against anything else, but it can also open up a new way of living. It makes everything more complicated and more interesting: the world becomes a vast multidimensional landscape in which every point of view must be taken into account. All we need to do is to remember this fact, so as to “become wise at our own expense,” as Montaigne put it.
Even for him, the discipline of attention required constant effort: “We must really strain our soul to be aware of our own fallibility.” The Essays helped. By writing them, he set himself up like a lab rat and stood over himself with notebook in hand. Each observed oddity made him rejoice. He even took pleasure in his memory lapses, for they reminded him of his failings and saved him from the error of insisting that he was always right.