I give here a few examples of the way in which the currently accepted realist attitude towards differences and distinctions may prevent us from adopting efficient methods of enquiry in philosophy and science.

But I am by no means claiming that the current way of thinking about distinctions is always misleading and always inefficient. The question whether a way of speaking or thinking is misleading depends upon the context in which it is used and also upon how clearly this context is determined. (See particularly the chapter on ‘Really and Merely*.) In order to bring this out I have chosen for my first example a case where the distinction in question can safely be treated as factual and where the realist attitude is therefore quite justified-provided that it is not taken too much for granted.