Filters through which the world is perceived I believe that we perceive and therefore know. We perceive through emotions, language and reason. These are also known as ways of knowing. Therefore, it is appropriate to use Woolman's twelve ways of knowing to talk about perception. Reality is what we see, hear, smell, touch, taste and feel. It is what we observe around us using our senses and sensations. However, how do we know that we are actually seeing reality and not our perception or something that our brain can accept and process? There are colors that our eyes cannot see, for example ultraviolet and infrared-red. These colors are invisible to the human eye so we cannot see them. What we perceive is a clean Singapore. How do we actually know that Singapore isn't littered with invisible rubbish? Of course, there are special devices that allow us to see these two colors and prove that such rubbish does not exist. However, we can never be sure that there are no other colors invisible to our naked eyes. The things we have always believed to be true because we have seen them with our own eyes may not actually exist so can we trust our eyes? Is what we see real? “My desk is in the study.” This statement, so-called "proof", is based on "unproven" premises and therefore nothing is true and reality is not real. This is skepticism. When can we be sure? We can only be sure of this when we begin with the simplest and most basic premises which are certainly impossible to doubt. This can be summed up in these three lines: "what we see is not real", "you cannot be sure whether you are dreaming or not", "there is only one thing you can be sure of and that is the awareness of your own existence ". Xenophanes once said that we can always learn more than we know, but we can never be sure that we have reached a final truth. So to truly see, believe, or believe is truly seeing.?