less agree without hesitation that the solid products of accurate and complete observation, natural or experimental, are the bed-rock of our group of sciences. The first great object sought by laudable methods is, therefore, the promotion of the most accurate, searching, exhaustive and unbiased observation that is possible. One of the primary efforts in behalf of our sciences, therefore, was naturally directed to the task of promoting the best observational work. It was soon discovered that two chief dangers threatened the worker—bias and incompleteness. To guard against the first there was evolved
The Method of Colorless Observation.
Under its guidance, the observer endeavors to keep his mind scrupulously free from prepossessions and favored views. However tensely he may strain his observing powers to see what is to be seen, he seeks solely a record of facts uncolored by preferences or prejudices. To this end, he restrains himself from theoretical indulgence, and modestly contents himself with being a recorder of nature. He does not presume to be its interpreter and prophet. At length, in the office, he gathers his observations into an assemblage, with such inferences and interpretations as flow from them spontaneously, but even then he guards himself against the prejudices of theoretical indulgence.
Laudable as this method is in its avoidance of partiality, it is none the less seriously defective. No one who goes into the field with a mind merely receptive, or merely alert to see what presents itself, however nerved to a high effort, will return laden with all that might be seen. Only a part of the elements and aspects of complex phenomena present themselves at once to even the best observational minds. Some parts of the complex are necessarily obscure. Some of the most significant elements are liable to be unimpressive. These unobtrusive but yet vital elements will certainly escape observation unless it is forced to seek them out, and to seek them out diligently, acutely and intensely. To make a reasonably complete set of observations, the mind must not only see what spontaneously arrests its attention, but it must immediately draw out from what it observes inferences, interpretations, and hypotheses to promote further observations. It must at once be seen that if a given inference is correct, certain collateral phenomena must accompany it. If another inference be correct, certain other phenomena must accompany it. If still a third interpretation be the true one, yet other phenomena must be present to give proof of it. Once these suggestions have arisen, the observer seeks out the phenomena that discriminate between them, and, under such stimulus, phenomena that would otherwise have wholly escaped attention at once come into view because the eye has now been focused for them. It may be affirmed with great confidence that without the active and instantaneous use of these concurrent processes the observer will rarely, if ever, record the whole of any one set of significant ele-
