Scepticism is generally regarded as a position which, if correct, would be disastrous for our everyday and scientific beliefs. According to this view, a sceptical argument is one that leads to the intuitively false conclusion that we cannot know anything. But there is another, much neglected and more radical form of scepticism, Pyrrhonism, which neither denies nor accepts the possibility of knowledge and is to be regarded not as a philosophical position so much as the expression of a philosophical way of life.
Professor Naess argues that, given a sympathetic interpretation, Sextus Empiricus's outline of Pyrrhonian scepticism provides the essentials of a genuine and rational sceptical view. He begins with a brief account of Pyrrhonism, then goes on to argue for the psychological possibility of this kind of scepticism, defending it against common objections to scepticism, and examining some of its psychological and social implications. The last two chapters provide detailed support for the rationality of Pyrrhonism, drawing mainly on certain methodological distinctions in semantics which both justify the Pyrrhonist's failure to make assertions and restrict the scope of recent epistemological arguments against scepticism in such a way as to modify severely the conclusions based on them.
Næss was a Norwegian philosopher, known foremost as the founder of the concept Deep Ecology Næss combined his ecological vision with Gandhian nonviolence and on several occasions participated in direct action events. He was the youngest person to ever be promoted to professor at Oslo University (27), a position he inhabited from 1939 to 1970. Næss' main philosophical work from the 1950s was entitled Interpretation and Preciseness. . He later developed the conclusions in that book into a simplified, practical textbook, entitled Communication and Argument, which became a valued introduction to pragmatics or rather "language logic", and was thus used over many decades as a sine qua non for the preparatory examination at the University of Oslo, later known as "Examen Philosophicum".
From the 1960s and forward his work came to be more and more focused on what would later be known as deep ecology. The name was first introduced to the public by Næss in 1972 during a lecture and was later explained further in The Shallow and the Deep Long-Range Ecology Movement: A Summary (published 1973 in the Inquiry journal).
Perhaps the best is in the summary by Naess himself:
"My conclusion on modern scepticism can be put as follows. If by scepticism or ‘epistemological scepticism’ is meant a doctrine expressible by ‘There can be nothing known’, ‘No statement can be known to be true’, or ‘No empirical statement can be true’ without essential and severe qualifications and reservations, then scepticism is untenable. If, however, the reservations and qualifications are made which are suggested in the foregoing, such scepticism is tenable."
If modern Pyrrhonism has to be useful, it has to be applied to certain moments in the conversation where the statement of truth is of utmost importance.
As such, Scepticism might be deployed for profit in a devastating way against all the innocent, everyday participants of the discussion.