I had a partner who teased me whenever I informed her that I’d worked something out in my own head. She had a sharp ear for pleonasm and so I made attempts to avoid being teased.
Recently, I discovered that the journal Radical Philosophy has been revived. The old one started in 1972 and ran to two hundred issues before running out of steam. This morning in the shower - and nearly fifty years after contributing to the first issue of the original Radical Philosophy  - I had the thought (in my own head), Isn’t the expression radical philosophy a pleonasm?
All philosophy tries to get to the root/s of things, to get beyond the repetition of conventional thoughts, the reliance on unchallenged assumptions, the polite acquiescence in received wisdom. That does not entail that philosophical conclusions must end up being sceptical in character. You may dig down to the roots and discover they are very strong and hold up the tree very well. Your task then becomes that of re-familiarising others, of getting them to look afresh at what has become so familiar that it is too much taken for granted. Take a look, give that root a big kick, and you will find it hurts you more than it hurts the root.
But to confine philosophy to just sceptical and non-sceptical versions is too limiting, anyway. Raymond Geuss titles a recent book Changing The Subject (2017) and broadly speaking argues that philosophers repeatedly change the state of the question. Marx was very explicit about the change he wanted to make: Philosophers have hitherto only interpreted the world in various ways; the point is to change it. 
It’s a commonplace in the philosophy of science at least since Thomas Kuhn’s work (1950s – 1960s) that when a scientific revolution occurs, it’s not just a theory which changes. It is the questions asked, the bits of the world which seem in need of study, the definition of the subject itself. Geuss is casting the history of philosophy as possessed by a similar dynamic.
But for both science and philosophy, it does not exclude the claim that they aim at truth.
There is art and literature which might be described as philosophical and which also tries to dig down to the roots, either to refresh our understanding of our world or suggest we might be better off shifting ourselves into a different one. William Wordsworth seeks to refresh, to re-imagine our familiar world, to give the charm of novelty to things of everyday as Coleridge puts it in Biographia Literaria.
In contrast, there are those who use literary and theatrical techniques of estrangement or alienation to upset our habitual responses, hoping to lead us into questioning the normal, into imagining a world different from this wearying reality of ours. In the recent past the names of Viktor Shklovsky and Bertolt Brecht  are closely linked to such an approach, but the techniques are not new. They are deployed in a long procession of older works in which the morals and manners of other cultures are held up as mirrors to our own.
Of course, art and literature and philosophy too are often enough produced as comfort food, offering no challenge and packaged like candy. On that, my philosopher’s advice is to refuse substitutes and only curl up on the sofa with real ideas and fairtrade chocolate. 
 “Sanity, Madness and the Problem of Knowledge”, Radical Philosophy, 1, January 1972, pp. 22-23. Now at academia.edu
 . The Eleventh Thesis on Feuerbach, dating from 1845.
 Thomas Kuhn, The Structure of Scientific Revolutions (1962).
 “English Formalism and Russian Formalism”, in my Materials and Medium: An Aesthetics (2016), pp. 71-80.
 Here Dr Pateman enters into competition with Dr Peterson who in 12 Rules for Life (2018) recommends a masculine diet of Heidegger and fry-up breakfasts. Cousin Medicine publicly despairs of us both but kindly whispers, Peterson’s diet is much worse.