Abstract

Are animals and humans different in kind or only different in degree when it comes to the mental springs of behavior? The source of this question is Charles Darwin's 1871 The Descent of Man, in which he argued for a difference in degree between animals and humans in mental abilities, rather than a difference in kind. Darwin's opponents in the ensuing debate were theologians and scientific traditionalists who insisted upon human specialness when it came to the mind,even if evolution held sway for explaining the body. In this paper I take up the same question, which has not gone away. Representing the continuity thesis is Donald R. Griffin, a zoologist who founded the field of cognitive ethology in the 1980s, and voicing the discontinuity thesis is Raymond Tallis, a neuroscientist and self-described humanist. Tallis's apparent mission is to protect human dignity from the onslaught of writing and research by evolutionary psychologists and sociobiologists, who claim to be demonstrating the evolutionary basis for all human mental capabilities, including higher reasoning and ethics. To raise humans up, Tallis lowers animals down, making disparaging remarks like, "Chimps are chumps." I defend the chimps by finding serious flaws in Tallis's reasoning. Tallis locates the crux ofthe cognitive difference between humans and nonhumans in the linguistic concept of intentionality. I present and counter his charge of a difference in kind by relying on empirical evidence provided by Griffin and others, and on my logical analysis of Tallis's claims. The paper has 3 sections: introduction, first point of argument, second point of argument, and concluding note.