I tend to share Horwich's point of view on this matter which is (as he claims) quite in line with that of Ludwig Wittgenstein. Horwich's very down-to-earth (and, again, Wittgensteinian) views on language and meaning also appeal to me.
But in other areas I have problems with both Horwich and Wittgenstein. My disagreements relate mainly to their views on (and intuitions about) ethics, religion and science.**
Clearly there is a (rough) divide between religious and non-religious thinkers. But, this division does not neatly mirror the the divide between classical rationalists and those of a more empirical cast of mind, between those who believe that pure human reasoning can reveal deep, a priori truths about the world and those who embrace the messiness and contingency of life and look to empirical science for a fundamental knowledge of the natural world.
This is mainly because many of those who reject the a priori of classical rationalism – and the claims of many rationalists that reason can access or reveal not only metaphysical but also religious truths – are still committed to religion. For them, some faculty other than reason (faith or intuition) provides knowledge of an entirely different and deeper reality than that with which human reason or logic or science is concerned. We may call these fideists (though the term can be used in a narrower sense).***
Historically speaking, fideism has arguably been more conducive to empirical enquiry than rationalism of the traditional kind. For example, the rise of fideism in the late Middle Ages can be seen to have helped to break the overweening and extravagant metaphysics of scholasticism. Natural theology was called into question, and logic and reasoning applied to more practical problems. This shift encouraged the development of empirical science and new technologies.
Certain religious traditions not only incorporate a rich and sophisticated understanding of human psychology, but also promote a healthy awareness of the pitfalls of pure reason and the limits of human understanding. In fact, when I was religious – roughly, between the ages of thirteen and twenty-one – I identified strongly with such (fideist) traditions.
But – there has to be a 'but', I'm afraid – traditional religious views are, in the light of modern science, just no longer tenable. Even the more sophisticated attempts to justify (often some very ill-defined form of) belief – along the lines, for example, of William James's famous essay, 'The will to believe' – strike me as at best unconvincing and at worst dishonest.
One's overall view of the world will be based on more than just science, of course. It will necessarily derive largely from commonsense knowledge and ordinary observation – and even from intuition (understood as a kind of practical understanding or knowledge derived from experience).
Such direct and personal insights are, however, necessarily limited in perspective. And science – with its objective, impersonal perspective, its 'view from nowhere' – is at the very least a necessary corrective.
So long as science is not too narrowly defined, no one in their right mind would deny this. So why is there so much hostility towards science amongst those educated in the arts and humanities (philosophers included)?****
Petty rivalries between discipline areas and professional resentments play a role, no doubt, but my best guess is that the main driving factor is a widely-felt and profound distaste not for science itself but rather for the kind of (almost alien) world which scientific research in various fields seems slowly to be revealing.
* Anti-naturalism in philosophy (I) and Anti-naturalism in philosophy(II).
** I must admit that I am less familiar with Horwich's views on these matters than I am with Wittgenstein's, and it may be that their views are not as close as I currently take them to be.
*** The term is commonly (and I think rightly) applied to the very anti-metaphysical Wittgenstein. I don't know how Horwich would react to being so labelled.
**** Paul Horwich may not be at fault here: he talks a lot about 'scientism' but generally uses the word in a focussed way – and specifically to highlight futile and inappropriate attempts within traditional philosophy to emulate science.