But, just as surely, most noes believe in something like what the Super-Naturalists would call faith—they search for transcendence and epiphany, practice some ritual, live some rite. True rationalists are as rare in life as actual deconstructionists are in university English departments, or true bisexuals in gay bars. In a lifetime spent in hotbeds of secularism, I have known perhaps two thoroughgoing rationalists—people who actually tried to eliminate intuition and navigate life by reasoning about it—and countless humanists, in Comte’s sense, people who don’t go in for God but are enthusiasts for transcendent meaning, for sacred pantheons and private chapels. They have some syncretic mixture of rituals: they polish menorahs or decorate Christmas trees, meditate upon the great beyond, say a silent prayer, light candles to the darkness. They talk without difficulty of souls and weapons of the spirit, and go to midnight Mass on Christmas Eve to hear the Gloria, and though they leave early, they leave fulfilled. You will know them by their faces; they are the weepy ones in the rear.
The former characterization is a straw man, the latter seems mostly disconnected from reality.
It is both unnecessary, undesirable, and probably impossible to be a "thoroughgoing rationalist" in Gopnick's sense. The world is far too complex, and our brains far too small, to reason through more than a tiny few, much less every, decision we face. We have good evidence to believe that the world is generalizable, and there is nothing disreputable about learning useful generalizations about the world by loose induction from experience or evolution (i.e. intuition), or even received wisdom. Good enough is good enough, and if intuition or received wisdom is good enough to get one through the day, lacking evidence to the contrary, there is no reason not to use it. For example, I have not made a detailed analysis of the best way to drive to school; instead, I have a route that seems (intuitively) good enough, and I use it. Furthermore, I do not bother to analyze the daily traffic that might suggest a better route for that day; I just stick to my existing route as good enough. A trivial example, to be sure, but an argument that is rebutted by a trivial example cannot be very good. Indeed, the "reason through everything standard is so unattainable that I strongly suspect the two "thoroughgoing rationalists" Gopnick mentions often use intuition and received wisdom. The idea navigating life by some sort of pure reason is nonsensical, so we need a better definition of the thoroughgoing rationalist. I consider a thoroughgoing rationalist, i.e. a skeptic, to be someone who wants to test any belief (stance on the truth or falsity of a proposition) by reason and evidence, is willing to test any belief by reason and evidence, and will in fact change his or her belief on the basis of these tests. We can still use intuition, rules of thumb, even received wisdom, but if there is a reason to subject that intuition to scrutiny, we will do so, and if our intuition is unreasonable, we will abandon it. But as a matter of practicality, if our intuition is good enough, we will use it until we have good reason to examine and possibly change it. Skepticism, therefore, is not a day-to-day methodology, but a meta-cognitive stance. It differentiates between those who are willing and able to subject all their beliefs to the test of reason and evidence, and those who hold back some beliefs from that test. There are plenty of the latter, and enough of the former to make the distinction relevant.
Gopnick's definition of rationalism is in error, but his depiction of humanism is both insulting and without foundation. It may be true that a few people call themselves humanists yet are still "enthusiasts for transcendent meaning" and the trappings of, and transcendent justification for, religion. Gopnick may have spent a lifetime "in hotbeds of secularism," but so have I, and my experience is different from his: I know absolutely zero of the kind of humanists he describe; I admit to a few only on the general principle that almost every describable behavior applies to at least a few people. In theory, humanism is the most un-transcendental moral philosophy imaginable: the foundation of moral reasoning is the actual well-being of real, living, breathing, concrete, un-transcendental human beings. I know a lot of liberal Christians (and a few liberal Muslims) who implicitly accept humanism but still mouth the platitudes of their religion, but I do not know any humanists who have explicitly renounced moral transcendentalism but still secretly yearn for it. There may be a few, but they are not only not typical, they are extremely rare. I can imagine only that Gopnick believes that everyone must necessarily yearn for transcendentalism, and anyone who explicitly renounces it must be fundamentally insincere. But it is simply untrue. We may still be in the minority with respect to the whole population, but people who call themselves humanists, at least those who I know, have no secret yearning for the transcendental.