We must conclude therefore that the processes of interpreting and appraising sensory input must unquestionably be assigned a causal role in producing whatever behaviour emerges. Like the other causal factors already discussed they are necessary but not often sufficient.

Regular monitoring both of behavioural progress and of consequences is of course necessary if the organism is to learn.

The fact that emotional feeling can be experienced during sleep is a reminder that not all processes having an emotional feeling phase originate in the environment.

Propositions of a genetic and adaptive sort are found throughout this book; and, in any theory of defence, there must be many of a structural kind. The points of view not adopted are the dynamic and the economic.

To ascribe feeling is usually to make a prediction about subsequent behaviour.

All knowledge is conjectural and... science progresses through new theories coming to replace older ones when it becomes clear that a new theory is able to make sense of a greater circle of phenomena than are comprehended and explained by the older one and is able to predict new phenomena more accurately.

Ever since Freud made his famous, and in my view disastrous, volte-face in 1897, when he decided that the childhood seductions he had believed to be aetiologically important were nothing more than the products of his patients’ imaginations, it has been extremely unfashionable to attribute psychopathology to real-life experiences.

Whoever may still be sceptical whether knowledge of animal behaviour can help our understanding of man can find no support from Freud.

We do as we have been done by.

If a community values its children, it must cherish its mothers.