Strength of Claims in Academic Prose: How not to set up a thesis you cannot support!

Relative: X may be true.  X may solve the problem.  X may explain the cause/effect.  X may explain the pattern I have discovered in the evidence.

Probable: X is probably true.  X probably solves the problem.  X probably explains best the cause/effect.  X probably explains best the pattern I have discovered in the evidence.

Absolute: X is true.  X solves the problem.  X explains the cause/effect.  X explains the pattern I have discovered in the evidence.

        At each stage, what does the author promise the reader the paper will do to properly support such a thesis, and how much do the stakes increase as the claim is strengthened from relative to probable to absolute?