2 50 THE AMERICAN JOURNAL OF SOCIOLOGY
We call these maxims principles of discoveiy. They are of pre-scientific origin, as above noted. They are nevertheless indispensable to science. No one of them alone is sufficient for the valuation of psychical facts. Together they constitute an indispensable machinery of reflection upon reality. They serve their purpose by setting research in motion.
In a similar way sociology, in its most general and formal shape, as we are now getting it organized, will be virtually a set of guiding principles for each social science.
CHAPTER V.
PRINCIPLES OF DISCOVERY IN THE PSYCHICAL SCIENCES.
A. THE PRINCIPLE OF SUBJECTIVE JUDGMENT.
The guiding principles of psychical science are, in one respect, different from the analogous presuppositions of physical science, viz., the former are much more evidently true within their own field. Such controversy as has been waged in physical science about the presence or absence of certain funda- mental relations has in psychical science never occurred ; e. g., mechani- cal causation vs. purpose in nature. There has been practically no dispute about the validity of judging others and their actions by ourselves ; or about the supposition that the events of the psychical world are not merely per- formances of individuals, but that the latter are themselves, in part at least, products of the psychical environment in which they appear ; or, finally, that individuals, like communities, are determined in some degree by nature. All these positions have been so generally accepted that they may almost pass as self-evident truths.
This situation is in close connection with the character of immediate real- ity which belongs to psychical knowledge, in contrast with our knowledge of nature. All the above mentioned heuristic principles of the psychical sciences are essentially psychological maxims, since they are fundamental to all psy- chological judgments, particularly those of practical life. Nevertheless, even here, controversy over ways of looking at the material is not wholly wanting. This contest refers, however, not to the applicability of these maxims, but to the extent of their application. Over the question of the weight to be allowed to each principle in proportion to the rest there are views so extreme that the one or the other of these principles is treated some- times as of no consequence whatever, and, on the other hand, as the deter- mining factor. Instead of tending toward settlement, this difference seems to be growing more pronounced than ever, perhaps because men are just becoming distinctly aware of the points of difference. This appears most clearly in the case of the first principle to be considered, viz., that of subjec- tive judgment. In spite of its self-evidence, it is capable of most divergent interpretation, so far as the kind and degree of its application are concerned.
Wherever we are conscious of phenomena outside of ourselves, which we
