Phenomenology of Spirit, Preface, paragraph 65

Indeed, non-speculative thinking also has its right, validity, albeit not heeded in the manner of speculative proposition. Abolishing the form of the proposition must take place not only in an immediate manner, through the mere content of the proposition. Rather, this counterposed movement must be expressed, and not only that internal restriction, but what must also be expounded is this return of the concept into itself. This process, which constitutes what formerly had to be accomplished by proof, is the internal dialectical movement of the proposition itself. This alone is the actual speculative, and only the expression thereof is speculative exposition. As proposition, the speculative aspect is merely the internal restriction and the non-existent return of essence into itself. Hence we often find philosophical expositions referring us to this inner contemplation, thereby sparing us the exposition of the dialectic movement of the proposition which all the while is what we wanted. The proposition ought to express what the true is, but in essence it is subject; being so, it is merely the dialectical movement, this self-generating, -leading, and in-itself-returning course. With other forms of cognition, the proof constitutes this side of the expressed inwardness. But once dialectic has been separated from proof, the concept of philosophical proof has indeed been lost.