The Greek word skeptikoi means investigator or examiner. Skepticism is a position of denial. Refuse to rule on the existence of objects. Judgement is suspended, perhaps permanently.
Definition of “Skeptic”
Sextus Empiricus summarizes this philosophy as follow:
“Skepticism is the ability to face to face things that appear as well as those thoughts in any manner whatsoever, in which capacity, because of equal strength there is in objects and opposing arguments we arrive first at the suspension of assent, and after that the peace” Sextus Empiricus
Skepticism is a philosophy based on the criterion of life, experience and phenomenon. The phenomenon, according to the Greeks at the time of Pyrrho, a physical reality that we can feel. E.g. an object emits (or reflects) the light. The eye emits radiation. The meeting of these two flows creates a kind of body, a physical object that constitutes the phenomenon.
The main consequence is that the object is never seen as itself. What we see is a kind of screen, which contains a mask, however, something of the subject (eg, bloodshot eye sees a phenomenon red). The perception is relative. When Plato concludes that we must be wary of the vision and know the ideas, he concludes that Pyrrho can not know at all. Skeptics do not deny the existence of only the appearance of being, of truth. So I can say, not that honey is sweet, but it seems like. We must therefore remain undecided.
Ænésidème develop a series of arguments to show that we can not perceive the essence of things. These are the tropes. For example, the sense organs are not the same depending on the animal species will therefore have different sensations. It can be concluded that the feeling is on the topic (first trope). Depending on the circumstances one man does not necessarily see the same object in the same way. Thus, according to a man is young or old, healthy or sick, in motion or at rest and so on., The sensation will vary. But it also varies by location, the position of the object, its distance (second, third and fourth tropes). Another argument points out that the customs, laws, beliefs vary. All these arguments show that sensible knowledge is relative and should therefore suspend its decision.
New skeptics (Agrippa, Sextus Empiricus) invent a new logic to prevent the soul of dogmatic based on five arguments:
The opinions clash, disagree. Any argument requires proof that, itself, must be proven and so on, so you can never get to the end (infinite regression). Objects are related to each other and any representation relates to a subject. For example, the left is on right, father to son and so on. and thus no universality is possible.
To escape the infinite regress, it must be from an unprovable and all reasoning is based on something unproven (argument of the hypothesis) or fall into the vicious circle in which A is shown by B and B by A (argument of diallel).
Note that Sextus Empiricus, far to reject any science, admits the validity of an experimental astronomy to address agricultural work or talk about how to measure time by the water clock. He criticized, however, uncompromising astrologers considered charlatans.
Morally, the skeptics deny the existence of an absolute good but admit the existence of better lives than others. The wisest course is to follow the customs of the most widespread and to be guided by experience and life.
The skepticism of the past, however, was considered a rule of life for its followers. Their goal was ataraxia, peace of mind, a state of perfect equanimity. Deny contributed appearances there in nothing but reject the dogmatism, though. Find ways to combat dogmatism has remained the central element of philosophical skepticism. Absolute certainty is not necessary, according to the skeptic, either in science or in everyday life. Science can manage very well, even limited to appearances and probabilities. You can find guidelines for daily life without resorting to absolute certainty. We are able to find the principles that lead us to what we want: a happy and peaceful. Many skeptics of the Greco-Roman period advocated a very conservative lifestyle, maintaining that it was better to rely on the nature and customs, including religious customs. They believed that following our natural appetites was generally a good rule of life. However, it seems that the social and political conservatism, while allowing most probably skeptical achieve ataraxia, leads to a false conclusion. Such a position is not a reasonable inference to moral skepticism or sensory. In addition, probabilism advocated by science seems to be sufficient for practical life.