IMO, if you deny that we have unmediated knowledge of the external world, that seems like it commits you to consider introspection as being the general case and observation of the external world as the particular special case.

@singer tough it is true we have no "unmediated knowledge of the external world", I'd assert we also lack "unmediated access" to our mental processes. The mediating vehicle is not our mind but instead our nervous system, of which our mind is only an emergent property of.

Unless you believe we live in a simulation, both types of observation are indirect using the nervous system as a vehicle, and I would even argue that arrangement allows less access to introspection than most forms of external observation.

@hidetzugu Certainly, introspection is mediated too. But external observation presents a persistent illusion that we are seeing something "out there". But the things we see "out there" are like details of a story within a story. The outer story is our mind, and is less fictional by one degree.

I think some answered No for conventional reasons about normal usage of the words, or they dislike the idea of observation being put on a level with introspection. But your perspective is one I'd associate with voting Yes.

This is particularly relevant to whether introspection is capable of demonstrating the reality of consciousness.