Born in the 5th century BC, Plato was a rationalist and idealistic philosopher, convinced that we are born with concepts within us and that these concepts are the same for everyone (Solomon, Higgins, & Martin, 2012). Through his beliefs, Plato developed a theory that he believed answered the question “What is reality?”, which he called the theory of forms (Solomon, et al., 2012). According to Plato, the Forms are the perfect ideal of an object or concept, immutable and innate within us (Solomon, et al., 2012). It is thanks to the Forms, according to Plato, that we have the ability to know what something is even though we may not have seen that exact thing before (Solomon, et al., 2012). According to Plato, an appearance is what you see. Appearance is what we see, it is subject to change while reality is the immutable Idea behind what we see. The reality of an object is in its essence, in its innate qualities that make the object that object. This is what Plato calls his Form. For example a pen. Its appearance is that of a pen. It has a long cylindrical shape, when you press on the paper the ink comes out. Its reality comes from the fact that we, as human beings, have the idea of ​​a pen. The fundamental principle of what a pen is and what a pen does. According to Plato everyone must have the same reality, since reality is in the essence of an object or concept (Solomon, et al., 2012). If the object or concept did not have an essence it would not be what you think, therefore reality is universal and immutable because if it changed it would not maintain the same essence, however matter, or appearance has the ability to change (Solomon, et al., 2010). The distinction Plato makes between... a medium of paper... an investigation into whether or not reality is universal. Another limitation of Plato's theory is when Plato says that things in the 'world of becoming' 'participate' in the Forms of the 'world of Being' (Solomon, et al., 2012). It might be suggested that the word “participate” is just a word, not an explanation of the relationship between the Form and the particular thing (Solomon, et al., 2012). Regarding this limitation, Plato himself found doubts, which he expressed through his later dialogues (Solomon, et al., 2012). It can be argued that Plato's theory of the Forms does not fully take into account all areas of knowledge or appearance and reality. without creating limitations. His theory suggests predicting a universal reality, however suggestions can be found as to how this may not be the case, provided it does not fully take universal reality into account.