In the case of a metaphysical problem, however, the empirical situation is more or less frozen. Consider the famous controversy between McTaggart and Russell concerning the question whether there is a moving NOW, and the many well-known arguments that have been advanced in favour of their respective positions. Each one of these arguments could have been put forward equally well in the context of scientific knowledge as it stood 50 or even 500 years ago. The empirical features of the universe that are relevant to the hypotheses of McTaggart and Russell remain virtually the same, and it is not expected that future empirical discoveries are going to have a crucial impact on the credibility of either hypothesis. Empirical, however, refers to knowledge derived only from experience.
Prior knowledge is too suspect to be included.
The idiosyncratic technique adopted by the astrologer according to the convention that every astrologer has to do things differently to every other, is combined ad hoc with elements of a hoary tradition that provide a priori knowledge. Empiricism specifically repudiates propositions in the realm of metaphysics. Since even animal species have since been proven to possess innate pattern-recognition abilities, this belief system is clearly redundant, an ideological cul de sac that civilisation has left in its wake. I believe the empirical attitude retains value and utility, but it must be complemented by acknowledgement of the existence of other psychological sources of information. We need communal strategies and techniques for gauging the merit of purported knowledge, to ascertain the extent of consensus and the extent that it can be seen to possess objectivity.