Plantinga’s Theistic Philosophy: The Existence of God is Immediate or Properly Basic.
The new approach of theistic philosophy establishes that “theistic belief in general and Christian belief in particular can be accepted with perfect rationality even if the believer doesn’t have any good arguments for this belief, and even if there aren’t any such arguments.” According to Plantinga, these arguments are the propositional evidence required by scientific methods. However, Plantinga argues that scientific methods cannot be applied to prove or explain the beliefs in God because these beliefs are immediate or properly basic.
Plantinga and the Sensus Divinitatis
Most philosophers agree there are some properly basic beliefs. These beliefs are innate to every human being. Considering such beliefs as a priori knowledge, Plantinga writes
God has therefore created us with cognitive faculties designed to enable us to achieve true beliefs with respect to a wide variety of propositions – propositions about our immediate environment, about our own interior lives, about the thoughts and experiences of other persons, about our universe at large, about right and wrong, about the whole realm of abstracta – numbers, properties, propositions, states of affairs, possible worlds and their like, about modality – what is necessary and possible – and about himself. These faculties work in such a way that under the appropriate circumstances we form the appropriate belief. More exactly, the appropriate belief is formed in us; in the typical case we do not decide to hold or form the belief in question, but simply find ourselves with it.
No one can deny the capacity to make moral choices is innate to every normal and healthy human being. No one can deny the capacity to keep memories is innate to every person who has his faculties working properly. This kind of a priori knowledge is settled on the basis of any other knowledge. It means that every other knowledge is built upon these properly basic beliefs. Although the scientific method cannot be applied to prove or explain these properly basic beliefs, no scientist or philosopher can deny the existence of the a priori knowledge.
Plantinga writes “the sensus divinitatis resembles the faculties of perception, memory, and a priori knowledge” Plantinga follows the idea of John Calvin in saying that the sensus divinitatis is a cognitive mechanism “which in a wide variety of circumstances produces in us beliefs about God. These circumstances trigger the disposition to form the beliefs in question. Under these circumstances we develop or form theistic beliefs.” Whenever a person contemplates the great beauty of nature, this sensus divinitatis provokes in her some kind of beliefs about God. Likewise, this sensus divinitatis triggers some kind of beliefs about God whenever a person faces a dangerous situation. These circumstances and other correlated experiences prove the idea about God is innate to every human being. Since the idea about God is an a priori knowledge, the scientific method cannot be applied to prove or explain it.
The Role of the Holy Spirit to Produce Faith in the Human Heart Through the Scriptures
Although the sensus divinitatis is a priori knowledge related to divinity, it does not necessarily point to the God of the Scripture. Alvin Plantinga affirms that sin affected the sensus divinitatis. He writes
Our original knowledge of God and of his marvelous beauty, glory, and loveliness has been severely compromised; in this way the broad image was damaged, distorted. In particular, the sensus divinitatis has been damaged and deformed; because of our fall into sin, we no longer know God in the same natural and unproblematic way in which we know each other and the world around us.
Therefore, it is impossible to know God only through the deliverances of the sensus divinitatis. No one can really know God through the stimulus of nature or rational arguments. Sin affected both the perceptive and cognitive aspects of all human beings. The perceptions and the mind do not function properly in the way for which they were designed. For that reason, the action of the Third Person of Trinity, the Holy Spirit, is essential in producing the right beliefs about both God and faith.
Considering the relation between the sensus divinitatis and the work of the Holy Spirit, Plantinga affirms,
There is an important difference between the sensus divinitatis and the internal instigation of the Holy Spirit. Where the sensus divinitatis is a part of humanity’s original cognitive equipment, the internal instigation of the Holy Spirit, whereby we come to realize the central truths of the gospel, is a special gift given by God that comes with salvation and is part of the process designed to produce faith. Hence, the internal instigation of the Holy Spirit is not a cognitive faculty in the same way that perception, memory, or even the sensus divinitatis are; it is a cognitive process or ‘a means by which belief, and belief on a certain set of topics, is regularly produced in regular ways.
The Holy Spirit uses Scripture – which is God’s testimony – to correct the sensus divinitatis, imparting right beliefs about God to human beings, and also generating faith in their hearts. Thus it is impossible to know God without both the testimony of Scripture and the work of the Holy Spirit.
The apologetic works of Alvin Plantinga establish a good philosophical foundation for the warrant of Christian belief. It proves that Christian belief is not irrational, but reasonable and rational. Belief in God is not secondary and built in other propositions, but properly basic and, therefore, immediate. Likewise, one does not ask for evidence to perceptual beliefs, one should not ask for evidence to belief in God. Therefore, requesting evidence to Christian belief is nonsense.
However, the apologetic works of Alvin Plantinga have some difficulties. Plantinga’s works support Christianity, but they also endorse other religion views. James Beilby writes
For example, couldn’t members of other world religions develop a model by which their beliefs could have warrant if they were true, just as Plantinga has? He [Plantinga] acknowledges just as much: “For any such set of beliefs, couldn’t we find a model under which the beliefs in question have warrant, and such that given the truth of those beliefs, there are no philosophical objections to the truth of the model? Well, probably something like that is true for the other theistic religions; Judaism, Islam, some forms of Hinduism, some forms of Buddhism, some forms of American Indian religion. Perhaps these religions are like Christianity in that they are subject to no de jure objections that are independent of de facto objections”.
Although Plantinga’s philosophical works had success in preserving the reasonableness of Christian Belief even without any evidence, Plantinga is still working on explaining Christianity as having the right sets of beliefs. Whenever he presents the primacy of Christianity, he does not use the arguments of philosophy to justify his thoughts, but the doctrines of Christian Theology like the instigation of the Holy Spirit and the testimony of Scripture.
 Alvin Plantinga, “On “Proper Basicality”” Philosophy and Phenomenological Research, November 2007, 614.
 Alvin Plantinga, “Justification and Theism,” Faith and Philosophy, 1988, 405-406.
 Alvin Plantinga, Knowledge and Christian Belief (Grand Rapids, MI: Eerdmans Publishing, 2015), 35.
 Ibid., p. 33.
 Alvin Plantinga, Knowledge and Christian Belief (Grand Rapids, MI: Eerdmans Publishing, 2015), 47.
 James Beilby, “Plantinga’s Model of Warranted Christian Belief,” ed. Deane-Peter Baker, in Alvin Plantinga (Contemporary Philosophy in Focus) (New York, NY: Cambridge University Press, 2007), 131.
 James Beilby, “Plantinga’s Model of Warranted Christian Belief,” ed. Deane-Peter Baker, in Alvin Plantinga (Contemporary Philosophy in Focus) (New York, NY: Cambridge University Press, 2007), 143-144.