For some time a consideration of philosophy as dependent only upon honesty has come to feel particularly apt for describing the unique situation the philosopher (and the interpreter of philosophy) finds himself. Due to the strangeness of this suggestion, and the general merit I feel in developing it further, I will exposit it and develop some directions for further consideration.
To be clear: honesty is not only required in philosophy. What I mean to emphasize here is that while other activities, such as science, have their special organizing concepts and principles assumed (even if they are not clear), the philosopher has none of these. So, while the scientist depends on some special principles and their honesty, the philosopher must simply remain honest. However, I also want to explain how the honesty demanded of the philosopher is unique.
Typically we can understand honesty in terms of not lying, and this holds for both philosophy and the sciences. Being dishonest in a science may involve falsifying or ignoring certain pieces of evidence in order to maintain something that should be abandoned or called into further question. We can also deceive ourselves by accidentally including evidence that should not properly be considered; this may mean the inclusion of bias or data that does not actually fit within the domain of the science. There is much more that can be said concerning this, and much more that can be clearer, but I will have this suffice.
The philosopher is in a different circumstance because there is no settled domain of objects, nor any principles which cannot be questioned: the 'work' of the philosopher is just as much a perennial problem of philosophy as anything else. Because of this, the philosopher need not worry about including objects or thoughts that are not in the domain of philosopher. However, precisely because the philosopher has no domain of objects that is settled the philosopher must be wary of all organization of thought that directs us, and must ask again and again into any such organization. This is where some difficulties in the philosophical life emerge, and which I can only deal with in terms of a reflection on the philosophical life.
When one opens up all sorts of questions, and strives towards pure contemplation, we typically develop anxieties of various sorts, and these lead to a tendency to end philosophical consideration by determining a principle. This succumbing to anxiety is how a philosopher can fail to be honest in their own contemplation, so far as the goal is pure contemplation.
Whenever the philosopher stops asking into the organization of thought or objects, and settles on some organization in order to advance, a science is established. This is no wicked thing, but for the purposes of keeping science clear in its aim (and to allow philosophy its problematic aim), it is important to see this distinction. From recognizing this risk of concealing the questionable from view, and considering this a dishonesty, it becomes clearer how particularly the philosopher can lose his way through dishonesty (even if this lose is at the same time a gain to science).
This sort of honesty where we challenge ourselves to understand more comprehensively whatever it is that we understand can, perhaps, help us understand the Delphic maxim, "know thyself", as well as help the reflection of other attempts at understanding philosophy.
If we suppose the philosophical lifestyle of contemplation is important in-itself (relative to life), perhaps it is important to consider exactly how we get pulled out of contemplation. What is it that allows anxiety to emerge? It is not simply a matter of pure thought, but a kind of dissonance between the world and our challenging of it and our role in it. Perhaps all our practical engagements are reflections of anxiety that constantly seek for a means to overcome whatever stifles our contemplative life and the world and denies us leisure? This seems like a productive line of inquiry for future work.