Natural selection is a mechanism for generating an exceedingly high degree of improbability.

Natural selection is a mechanism for generating an exceedingly high degree of improbability.

We have usually no knowledge that any one factor will exert its effects independently of all others that can be varied, or that its effects are particularly simply related to variations in these other factors.

In scientific subjects, the natural remedy for dogmatism has been found in research.

We have the duty of formulating, of summarizing, and of communicating our conclusions, in intelligible form, in recognition of the right of other free minds to utilize them in making their own decisions.

If ... we choose a group of social phenomena with no antecedent knowledge of the causation or absence of causation among them, then the calculation of correlation coefficients, total or partial, will not advance us a step toward evaluating the importance of the causes at work.

Experimental observations are only experience carefully planned in advance, and designed to form a secure basis of new knowledge.