A gloss is a total system of perception and language.
From all this it follows what the general character of the problem of the development of a body of scientific knowledge is, in so far as it depends on elements internal to science itself.
It is probably safe to say that all the changes of factual knowledge which have led to the relativity theory, resulting in a very great theoretical development, are completely trivial from any point of view except their relevance to the structure of a theoretical system.
But the fact a person denies that he is theorising is no reason for taking him at his word and failing to investigate what implicit theory is involved in his statements.
If observed facts of undoubted accuracy will not fit any of the alternatives it leaves open, the system itself is in need of reconstruction.
Empirical interest will be in the facts so far as they are relevant to the solution of these problems.
The implications of these considerations justify the statement that all empirically verifiable knowledge even the commonsense knowledge of everyday life – involves implicitly, if not explicitly, systematic theory in this sense.
It is that of increasing knowledge of empirical fact, intimately combined with changing interpretations of this body of fact – hence changing general statements about it – and, not least, a changing a structure of the theoretical system.
Spencer’s god was Evolution, sometimes also called Progress.
A theoretical system does not merely state facts which have been observed and that logically deducible relations to other facts which have also been observed.