This philosophical analysis of the problem of “human nature” casts a strong and rare light on one of the most important questions ever asked.
What is this thing called Man? In the first place he’s an enigma, or, in the words of Jacob Needleman, “partly divine and partly an animal that reads.” From ancient times man has been exalted as a being above all the other animals, holding mastery over the rest of creation by virtue of his intellectual power and his special relationship with God or, anyway, with ultimate reality. On the other hand, since the advent of modern science and particularly since the publication of Darwin’s The Origin of Species and The Descent of Man, the species known as Homo sapiens has come to be seen as one organism among the many that make up the natural biological world, possessing unique and distinctive traits to be sure, but only in the sense that every other animal does as well. Man is the smartest land animal in the same way that the elephant is the heaviest and the cheetah the fastest.
This latter view is generally the view of the modern world and certainly that of modern science. But, as Mortimer J. Adler shows, we’re not very consistent about this, and we certainly have not worked through the implications for our attitudes about society, law, and rights. He’s convinced that if we wish to be governed by principles and by reason, it makes the biggest possible difference what our view of human nature is. For if man is really just one animal among many, then there can be no fundamental reason to justify treating humans and animals differently. We may not like what Hitler did to Jews, gypsies, and Jehovah’s Witnesses, but our modern scientific view of human nature gives us no principled reason to criticize his regarding those humans as animals and treating them as such. True, Hitler was an animal too, but, he would say, a superior animal—and there lies the crux.
No one denies that man is an animal. The question is whether he is also anything more or other than that. Adler finds that the issue boils down to this: does man differ from all other animals in kind, or only in degree? He further examines the question of what it means to differ in kind, and finds that there are exactly two ways: a superficial way, which arises when a difference in degree passes a certain threshold that causes a jump in capability; or a radical way, which arises when a trait possessed by one creature is not possessed in any degree by another. In other words, if man is radically different in kind from other animals, then he possesses one or more traits that are not possessed at all by any other animal, and no amount of increasing other animals’ existing traits will bring them any closer to humanity.
Adler takes his time developing his argument, and I found him sometimes repetitive in rephrasing and recapitulating his points, which made the book a bit longer than it needed to be. But I was very impressed with his rigor and his fearlessness in working through the issues in detail. I was also very impressed with his level of authority on this topic.
What do I mean by that? I mean that Adler, rather than being one arguer among many in this debate, brings a greater detachment, a much deeper education in the history of the topic, and perhaps most of all a keener insight into the consequences of its resolution for human society and the justice attainable within it. (That said, I think that Adler differs only in degree from his adversaries—not in kind!) As editor of the Encyclopedia Britannica and co-editor of the Britannica Great Books series, Adler brings a unique degree of background knowledge to the discussion. Indeed, his essay on “Man” in volume 3 of The Great Books makes an excellent warmup for reading this book.
Adler regards the question of human nature a “mixed” one—that is, a question that can be answered only by a combination of philosophical and scientific methods. He believes that psychologists, zoologists, and computer scientists have as much to contribute to the question as philosophers do, and expects (writing in 1967) a definite—or definite enough—answer to the question in the future. At the end of the book he sketches what he believes will be the implications of either answer to the question (the key difference turns out to be whether humans are or are not radically different in kind from other animals.)
In all I found Adler’s treatment of the topic serious, cogent, and forceful. He really helped to make clear and definite many things that were fuzzy and confused in my mind. Possibly because my own spiritual and philosophical training, such as it is, has been Buddhist, I felt that the argument did not actually cover the whole terrain. Adler’s viewpoint and background are unabashedly Western, and I felt that, despite his unswerving effort to be impartial and objective, he accepts certain ideas without question, or at least regards them as demonstrated beyond doubt. One of these is that perceptions, unlike conceptions, are a physical, material phenomenon. As far as I can tell, a “perception” is as much an intangible, mental phenomenon as a “conception” is, and if this is so, it has important, even decisive, implications for Adler’s argument.
But even if that’s the case, this book is extremely valuable and should be required reading for anyone who wants to participate in the discussion of human rights, animal rights, or the environment. In other words, so far from going out of date, Adler’s book is becoming more timely with each passing day.