The our rudimentary sense organs can possibly deceive us.

The philosophical attitude of the skeptic calls into examination the validity of our basic sense-based beliefs. John Pollock and Michael Huemer both go so far as to argue that we are unable to justify belief in an external world. Both arguments will give us a better understanding of how our rudimentary sense organs can possibly deceive us. Skepticism can give us insights into alternatives of evaluating and acknowledging the external world. In this essay, I will examine the key premises illustrated by both Pollock and Hummer in detail, but also analyze our awareness and perspective of the external world and why our view is not what we actually see. I will also defend the tenets of skepticism and the arguments that support it. 
Pure skeptics are not really doubters. The word skepticism in Greek is skepsis which along these lines implies that inquisitive minds have been hypothesizing and pondering since the time of the Ancient Greeks. Skeptics utilize motivation to elucidate their musings and thoughts to propel their arguments (Unger, 198). The concept of the skeptic is essential to understand because, on the grounds of the true skeptic, they are inseparably unique in relation to the pure rejecter, who transparently rejects all evidence opposite their own point of view. In terms of skepticism, skeptics set a particular standard for reasoning in which to approach in various positions in an argument. The skeptical attitudes displayed by skeptics have been the impetus for the creative and evolutionary ideas presented in arguments defending those positions. 
In defending the skeptic, the external world is in opposition to our awareness. The vast majority of what we accept or find in the world originates from our encounters. Some philosophers, like Huemer, theorize that our beliefs and ideas come from experience.  We frequently believe that the origins of our experiences are material objects. The presence of such objects is basically in the external world. One of the fundamental attributes of the outside world is that it lives autonomously of any event whatsoever (Huemer, 195). That is, for instance, if a winged animal had existence in the external world, at that point it would exist whether it was being seen or not. In any case, if the flying creature exists just in the event that somebody comprehended that it existed, at that point, it is absent in the outside world.
People make an association between something being actual and inside the head. Fantasies are ideas that live inside the head. Assuming dreams exists, does not reject the experience as functional, or that the reasons behind the experience are sensible. For it being inside your head, rejects the criticalness that it exists openly of the experience. At the point when an individual quits having a specific dream, the dream does not continue existing inside someone else. Ordinarily, objects differentiate from what is inside our heads (Huemer, 200). They exist outside of the head like the external world. The three arguments made by Huemer try to state the stance of the skeptic. Mike Huemer represents in his beginning two premises that humans lack recognition of extraneous subjects and the last thesis examines a moderate stance that discusses the lack of external items in the world. 
The starting premise made by Huemer is called the infinite regress. This proposition is constructed from a visceral awareness that aims to verify epistemic claims.
For us to verify that we recognize some premise U, we would need to have a little awareness of another argument S, that could assist in explaining my knowledge of U. In order to fundamentally establish my knowledge of S, I might be required to have some knowledge of a third proposition T, and so forth. The claims made can be grounded circularly between each other, but the structure does not suffice for justifying basic knowledge. In terms of this argument, one can attempt to avoid the regress model and construct a starting point for the series of basic knowledge claims. However, proposing a new point causes problems for the epistemic status of the claim being used. Huemer would acknowledge the type of response to the first argument and then would strengthen the position of the skeptic by responding to a probable objection. Huemer takes note that the other thinkers believe there is a blemish in the starting principle, thus they would state contrary to it, and that foundational propositions can let “one recognize it to be legitimate without having a reasonable reason” (Huemer,10). With this possible objection, Mike Huemer believes the skeptic has a response.
A skeptic can contend that an individual needs to have the capability to provide a way of determining between a foundational argument (e.g. 2=2) or a conscious one (e.g. a twelve-headed monster on Mars) (Huemer,10). The skeptic can denote that there is no foundational proposition since one proposition has to have a feature attached to it, thus provides a reason for the starting proposition. So the beginning is not foundational because it provides a reason for the feature and it does not distinguish between other propositions.
The second argument Huemer raises based on the skeptic, is the problem of the criterion. This premise raises some points based on circular reasoning, but it is solely associated with a central claim that we can only trust certain judgments created by a particular method (e.g. reasoning) f we know autonomously that the mechanism is reliable. However, the mechanism itself to test its reliability would trigger a circularity dilemma. If we attempt to use another method, we can have the ability to ask why that second method was reliable. Since we do not have endless possibilities of methods to construct judgments, and since none of the mechanisms can free themselves, it seems we cannot explain why any of the methods are reliable. And so, if none of the mechanisms forming the judgments are not reliable, then we should not trust any judgments produced by those methods. So the skeptic would ask two challenge questions: how can one justify the particular method that an individual utilizes in generating basic beliefs about the contingent state of affairs and how can one justify the reasoning methods that one uses to determine if it is deductive or inductive? These are the questions the skeptic would ask regarding the problem of criterion and the effects of the method used to test the reliability of perception.
The third premise by Huemer investigates the authenticity of our faculties in relationship to our perspective of the external world. Mike Huemer observes that our insight into the external world gives off an impression that we are reliant on our senses. A skeptic would espouse Huemer’s point and then will try to show that there is no way in trusting our sense organs to flawlessly depict our world to us as it is. First, the skeptic argues that what we obtain from our perceptions are not explicit images of the external word, but simply sense data. For example, you do not actually see a piece of paper in front of you, but a mental image of the paper itself. Huemer also notes that you cannot have knowledge of an external world unless direct realism or indirect realism is true.  Direct realism is the idea that are sense organs can grant us explicit access to external objects and indirect realism is the concept that uses the senses to detect objects internally, opposite of what exists in nature (Brown, 349). However, both concepts are false. Thus, in Huemer’s case the third argument is the strongest argument because it provides us insights into the differentiation of what we actually see and our experience through mental images. 
Huemer’s theory of the third premise agrees with the skeptic in that no physical item divides  into two separate things and thus no physical object exists in the external world. We would know the external world exists, if our sensory data induces material objects (Huemer, 200). Therefore, we are not conscious that our sense data is induced by objects and consequently there is no existence of knowledge in the external world. In the Brain in the Vat argument, Pollock theorizes that our experience through our sense organs is the only way we have access to the external world. In the story, the guy had his brain removed thus his images were screwed because he could not reprocess former objects in time. 
His brain was attached to a computer that can ultimately create simulated encounters of the external world (Pollock, 195). The skeptic would note that we cannot be sure that we are the brain in the that container or that our ideas about the world are totally false. In terms of our senses this argument was defended using a conclusion: I think the sky is blue, no brain in a vat can think the sky is blue, thus individuals are not programmed brains in a  container.  The critical conjecture in this argument is that one does not have proof contrary to the premise at hand, so one cannot have the right to rejecting since they have a lack of justification. If the reasoning in this argument was firmly logical, then this experiment would have been highly vital for skeptical philosophy, however it shows that we do not have sufficient justification of the external world. Huemer and Pollock provides us with arguments and conjectures to help shape our interpretation of the external world. Overall, these ideas can help mold our beliefs about perception and self-awareness of external forces at hand. 
Works Cited 
Brown, Harold I. “Direct realism, indirect realism, and epistemology.” Philosophy and Phenomenological Research 52.2 (1992): 341-363.
Huemer, Michael. Skepticism and the Veil of Perception. Rowman & Littlefield Publishers, 2001.
Unger, Peter. “A defense of skepticism.” The Philosophical Review (1971): 198-219.