"[T]here is every reason to believe that we were gregarious animals before we became men... And a belief in the eject—…"

"It may not be logical, but to my imagination, it is far more satisfactory to look at the young cuckoo ejecting its fo…"

"Among animals, some learn to speak and sing; they remember tunes, and strike the notes as exactly as a musician. Othe…"

"In no case may we interpret an action as the outcome of the exercise of a higher psychical faculty, if it can be inte…"

"[W]e must steadily bear in mind the sense in which the term "reasoning" is employed. If we apply this term to the pro…"

"[T]he phenomena which constitute the subject-matter of Comparative Psychology... have at least as great a claim to ac…"

"[M]ental activities in other organisms can never be to us objects of direct knowledge... we can only infer their exis…"

"The statements about human nature made by psychologists are of two sorts,—statements about consciousness, about the i…"

"The geographic location of origin can be inferred from the geographic distribution of certain alleles or lineages as …"

"Hunting by humans played a major role in extirpating terrestrial megafauna on several continents and megafaunal loss …"