“The function of the heart is to pump blood”, this statement is true because the heart has a systematic relationship with the body. Without the heart, the blood cannot flow throughout our body; and without the blood, there is nothing for the body to pump. So the definition of a function in this case is an assigned duty or a specific role of the heart. The function of the heart has a goal. Although, according to Aquinas’s goal-directed systems of “act for an end”, meaning everything is goal directed, however, the heart may have an end, but may not have a mind. Thus it would make sense that the heart just so happens to have a purpose through its mindless being.
According to the second statement, “the function of rain is to provide farm crops with water”, seems to be telling us that the sole purpose of rain is to provide water for crops. However, rain and crops does not have a systematic relationship with one another. If the statement is true, then it would mean that rain only falls on places with crops. If we follow this statement, then I understand now why it never rains my backyard, here, in Surrey, because I don’t have any crops for rain to water. So obviously, this statement is to be rejected. The definition of the word function is different from our first statement because “rain” just falls; it has no purpose or a goal in life to fulfill. Rain is accidental, and not thought of as a large system. It provides water for crops, but it is not its purpose.
To conclude this discussion, a purpose can be put into mindless things, like our heart. The goal doesn’t exist yet, but mindless, it has a purpose of doing things. Therefore, a function or a goal can only be applied to the first statement, but not to the second statement. With the first statement we could conclude with a random hypothesis, that the heart was accidentally produced by random happenings of things in the world rather than being designed by an intelligent being as Aquinas has claimed. Rain...