Robert N. Meroney, Ph.D. is an Emeritus Professor of Fluid Mechanics and Wind Engineering with a long career at Colorado State University.
Why does man fight? There are two primary theories.
1.) Prussian officer Carl von Clausewitz proposed war is a “continuation of policy . . . by other means.” War is another way that nations advance their own interests, a gainful enterprise, a rational action, or socially sanctioned group behavior.
2.) Sigmund Freud concluded there is a flaw in human psyche, a desire to destroy, an aggressive instinct, an irrational behavior that leads to war.
Some believe that Freud’s conclusion can be explained by our basic genome. Ever since the development of the theory of evolution proposed by Charles Darwin (1859), which suggested that humans were a natural consequence of the laws of nature, people have debated how “animal like” are humans. Initially, evolutionary scholars argued that a sudden increase in cranial capacity allowed man to step beyond animal instincts to kill for food to a human capable of spirituality and morals. This theory was supported by the discovery of the large sized Piltdown skull. But when this was shown to be a fraud in 1953, many researchers returned to the idea that man’s nature was basically driven by its ape ancestors who routinely killed to eat; thus, man, the killer ape.
Raymond Dart in 1953 posited that the cruelty of man can only be explained by “man’s carnivorous and cannibalistic origin.” Robert Ardrey (1961 to 1976) even argued that it was competition, violence and war that keeps man evolving, and without these activities mankind is doomed to dwindle to near extinction like the gorilla or entirely disappear like the dodo (Raphus cucullatus) last sighted in 1662.
The killer ape hypothesis is only one of at least twelve theories of how mankind evolved, and most do not stress a violent animal nature. Different scientists have proposed that humankind was uniquely determined because: we make tools, 1944; we’re killers, 1953; we share food, 1960s-70s; we swim in the nude, 2013; we throw stuff, 2013; we hunt, 1968; we trade food for sex, 1981; we eat (cooked) meat, 1992; we eat (cooked) carbs, 2015; we walk on two feet, 1809-1899; we adapt to climate change, 1996; and we unite and conquer as an invasive species, 2015. Many of these ideas may have merit, but they share a bias that each proposer believed that it was one well-defined trait that changed ape into man. Critics argue there is nothing in any proposal that causes inevitable change to a man from a toolmaking, stone throwing, meat and potato eating, highly cooperative, adaptable and big brained pre-man.
There is also the view of Social Darwinism and Sociobiology adherents that human morality should be based on the evolutionary process of the survival of the fittest. Individuals, ethnic groups, races, or societies that are most fit survive, and the weak are eliminated….and that is good! Thus, competition and winning are the basis of human morality and ethics. Ethical principles are only good if they allow the human race to survive, otherwise they are irrelevant. These arguments seem to be equally popular among laissez-faire capitalists, Nazi fascists, imperialists, eugenics supporters, nationalists and racists. These ideas have led to so many inconsistent and incompatible ideas that today it is criticized as an inconsistent philosophy, which does not lead to any clear conclusions. Critics also suggest that although genes might play a role, aggressiveness could as easily be explained by social environment, i.e., is it nature or nurture?
That man has an inherently aggressive nature is also frequently stressed by theologians who find it compatible with the idea of the originally sinful nature of mankind. Do you remember the old comic line “The Devil made me do it!” made famous by the comedian, Flip Wilson’s Geraldine Jones character? Some might find it comforting that this suggest our “inherent” violence and war propensities aren’t our fault…the devil makes us do it!
Robert Sussman argues that even if there is some truth in aggressive human instincts, it is still possible for humans to deliberately choose NOT to be violent. We need not deny our demons, but we can be masters of our own future. We have the capacity to learn from our past, we need not be governed by it.4 Barbara Ehrenreich concludes her book on the origins of war by noting that one new and unique result of the many centuries of war is the arise of the world-wide peace movement and resistance to the institution of war itself. These movements are still very small and feeble relative to their opponents, and often reactive and tardy. But the author feels they are the primary hope against future war.1
A song for peace from Bob Meroney: “Here is an unusual song/poem by Burl Ives that speaks to the personal loss associated with war. One of my favorites, although it brings tears to my eyes.”
 Ehrenreich, Barbara (1997) Blood Rites: Origins and History of the Passions of War, Metropolitan Books, Henry Holt and Company, New York, 292 pp.
 Charles Darwin visualized a spiritual and intellectual gap between humans and their closest ape cousins. He noted that man was capable of love for all living creatures a trait seemingly absent in all other animals.
 Strauss, Mark (2015) 12 Theories of How We Became Human and Why They’re All Wrong, National Geographic, https://news.nationalgeographic.com/2015/09/150911-how-we-became-human-theories-evolution-science/
 Sussman, Robert W. (1999) The Myth of Man the Hunter, Man the Killer and the Evolution of Human Morality, Zygon: Journal of Religion & Science, Vol. 34, Issue 3, pp. 453-471. Also republished in 2013 as Why the Legend of the Killer Ape Never Dies, Chapter 6 in War, Peace, and Human Nature: The Convergence of evolutionary and Cultural Views (ed. Douglas P. Fry), Oxford Scholarship on Line.
 Social Darwinism, https://en.wikipedia.org/wiki/Social_Darwinism#Criticism_and_controversy