Agrippa (Greek: Ἀγρίππας) was a Pyrrhonist philosopher who probably lived towards the end of the 1st century CE.
[1] He is regarded as the author of "The Five Tropes (or Modes, in Greek: τρόποι) of Agrippa", which are purported to establish the necessity of suspending judgment (epoché).
We have the mode from hypothesis when the Dogmatists, being thrown back ad infinitum, begin from something which they do not establish but claim to assume simply and without proof in virtue of a concession.
[2] The three additional ones show a progress in the Pyrrhonist system, building upon the objections derived from the fallibility of sense and opinion to more abstract and metaphysical grounds.
According to Victor Brochard "the five tropes can be regarded as the most radical and most precise formulation of philosophical skepticism that has ever been given.