Identify important features of Aquinas’s and Clarke’s arguments and how the two differ from eachother, and articulate objections raised against each.

The main argument of both Thomas Aquinas and Samuel Clarke is known in philosophy, religion, and theology as The Cosmological Argument. Cosmology is the study of the universe and its origins; the cosmological argument, therefore, is an a posteriori argument based on the premise that the universe does exist and is also susceptible to change. However, for it to change, there must be an outer power or something/someone who is not a part of this universe and who has the ability to change, create, and even explain its existence and purpose. Thus, the cosmological argument is one of the most popular arguments used to prove and explain the existence of God.
Thomas Aquinas introduced five such arguments which are known as the Five Ways:
The First Way, Argument from Motion: everything moves, however, nothing can move itself; thus, there must be a being that will set everything into motion. This first mover is known as God.
The Second Way, Argument from Efficient Causality: nothing can cause itself to exist, therefore there must a being which causes the existence of all other beings; this first causer is God.
The Third Way, Argument from Contingency: there is a being responsible for the creation of all other contingent beings and has no creator of its own; this being is God.
The Fourth Way, Argument from Gradation of Being or Degrees of Being: Aquinas attempted to prove that there is a being which determines the characteristics of other beings; thus, some beings are good, while others are not so good, but they all owe their existence to God.
The Fifth Way, Argument from Final Causality (i.e., the teleological argument): Aquinas claims that there is a being which steers the lives of other beings and determines their goals and destinies. This being is God.
Unlike Aquinas, Samuel Clarke believed that every being or entity is completely and existentially dependent on the being or entity before it. Thus, we have an infinite series of dependent events. This is, in fact, the main difference between the two; Clarke accepted that beings have existed for eternity, while Aquinas didn't. Instead of focusing on necessity and contingency like Aquinas did, Clarke focused on self-existent, dependent, and independent beings.
Similarly to Aquinas, however, Clarke believed that everything happens for a reason—everything has an explanation. He also believed that not all beings are contingent and that there must be a self-existent, necessary, and independent being which can cause the existence of all other dependent beings; in other words, a being which has, basically, started the whole infinite series of dependent events. Clarke argued that this first causer is God.
There are numerous objections to both Aquinas's and Clarke's claims and arguments; however, they can be summarized in two philosophical questions:
If everything in this universe happens for a cause or a reason and if everything can be explained, then shouldn't we be able to explain the existence of God as well?
If God as a necessary, self-existent and supreme deity does not need an explanation, then why should we try to explain everything else?