If you confine yourself to this Skinnerian technique, you study nothing but the learning apparatus and you leave out everything that is different in octopi, crustaceans, insects and vertebrates. In other words, you leave out everything that makes a pigeon a pigeon, a rat a rat, a man a man, and, above all, a healthy man healthy and a sick man sick.

The instinctive need to be the member of a closely knit group fighting for common ideals may grow so strong that it becomes inessential what these ideals are.

In nature we find not only that which is expedient, but also everything which is not so inexpedient as to endanger the existence of the species.

One of the most dangerously vicious circles menacing the continued existence of all mankind arises through that grim striving for the highest possible position within the ranked order, in other words, the reckless pursuit of power which combines with an insatiable greed of neurotic proportions that the results of acquired power confer.

Truth in science can be defined as the working hypothesis best suited to open the way to the next better one.

The bond with a dog is as lasting as the ties of this earth can ever be.

Barking dogs may occasionally bite, but laughing men hardly ever shoot!