Introduction is given to the consciousness by the senses, has been taken by empiricist philosophers and some of those who affected by them to be the ground of the whole other human knowledge. But empiricist philosophers were unable to reestablish all of our common knowledge exclusively on the basis of the shortlist of those simple properties that supposed to be the given. Because they included only low-level properties on their list of the given properties. Edmund Husserl in the twentieth century creatively enlarged the list of the properties that were taken to be given. He suggests that we have "intuition" of some more specific state in the world ether. But he didn’t supply his theory with an objective method of determining which properties are given. Siegel’s method of phenomenal contrast is exactly the ground that enables us to decide what is perceptually given and what is not.

1. Visual phenomenal experience

we could go any further, we need a distinction; when we see a pine tree, for example, we can see it from different perspectives, with different feelings, different memories and different beliefs. Each of These differences may change the way in which the pine tree appears. Thus we can talk about seeing a pine tree in a wild and also a narrow sense: according to the wide sense, a state of seeing is to be individuated by its external object. In the narrow sense, rather, each way in which an object could appear create another seeing state. So we can have many different states of seeing a pine tree in a narrow sense but only one state of seeing a pine tree in the wide sense. The narrow sense has been also called by Siegel the visual phenomenal experience and sometimes just visual experience. (Siegel: 2010)

2. The visual experience of natural kind properties and the theories of perception

the case that we visually experience natural kind properties, sense-data theory could not be defended anymore; for it is impossible for any sense- data to be a natural kind at the same time. Adverbial theories also will have to be excluded. This limitation exerted on the philosophical theories of perception is an additional source of significance for our debate.

3. The method of phenomenal contrast as a general logic of inference argue that the experimental strategy that recently developed notably by Ned block (2014) to testify the hypothesis of visual experience of facial expressions, is, in fact, another application of Siegel’s general method of phenomenal contrast; Regardless of creative usage of empirical technique in Block’s argument, he follows the same logical steps that Siegel had been fully characterized before: Ned block provides an example of phenomenal contrast by pairing two different visual experience of the same ambiguous facial expression, and then try to exclude some of the alternative explanations for this contrast (Block 2014). But he does not put himself into trouble of discussing and rejecting all alternative explanations that are logically possible.

4. The visual experience of Natural kind properties

the second main goal of our paper is to defend Siegel’s argument for the representation of natural kinds in some of the visual experiences. Our strategy is to reject what we think to be the most reasonable criticism of the argument. The first objection made by Brogaard suggests that there is a cognitive state namely “seeming” rather than “seeing” which can provide a better explanation of Siegel’s phenomenal contrast as a difference in cognitive rather than perceptual phenomenology. (Brogaard: 2013) We rejected this criticism by showing that even a difference in the so-called state of seeming requires some difference in attention and hence some difference in what is perceived.

The second significant objection is been suggested by Rene Jagnow. He argues that Siegel does not fully characterize the proposal of the shape-gestalt properties (Jagnow: 2015) according to his argument the case of Chef/dog figure, illuminates that Different Shape-gestalts, organize the overall shapes in different part-whole structures. Thus two shape-gestalt could be different even if the overall shape of the two seems alike. (Ibid) But this objection-we argue- could not be applied to Siegel’s examples of tools with the same shape-gestalt like guns, hair driers, and drills; In the case of Siegel’s examples, in addition to similarities in overall shape of gun, hair drier and drill, they also organized in the same part-whole relation which obviously distinguishes them from the case of Chef/dog figure. Hence they truly have one and the same shape-gestalt which means that shape-gestalt properties cannot explain the phenomenal effect of the familiarity with pine trees.

Conclusion 

The hypothesis that natural kind properties can be visually represented is a significant hypothesis for the philosophy of perception. Furthermore, the method of phenomenal contrast is important because it explicates the general logical steps which one has to take- whether explicitly or not- if one is intended to determine the content of experience based on its phenomenology. The application of this method also shows that the natural kind properties could be represented in visual phenomena experience and that criticism against this application of the method of phenomenal contrast that mentioned here, don't work.

References

-      Siegel, S. (2010) The contents of visual experience. Oxford: Oxford University Press.

-      Brogaard, B. (2013) "Do we perceive natural kind properties?" Philosophical Studies, 162.

-      Jagnow, R. (2015) "Can we see natural kind properties?", Epistemology & Philosophy Of Science, 2015, Ò. XLIV _¹2 

-      Block, N. (2014) "Seeing as in the light of vision science", Philosophy and Phenomenological Research.