God has no beginning and no end because God is unimaginable. The beginning and the end must be also unimaginable for an unimaginable item. The creator cannot be any item of the creation. If creator becomes creation, there must be some other creator for this creator to become the creation. Ad-infinitum (Anavastha) results. Science disproved some conclusions of the earlier logic and this should not be misunderstood as refusing God. God is in no way touched because the earlier logic also was dealing with only the analysis of created items. Tarka means the analysis of the items of creation, which are indicated and understood by their corresponding names or words (Tarkyante Padarthah Asminniti….). God is beyond all the words and cannot be the understood meaning of any word and therefore, logic cannot touch God.
Today science is the most advanced logic since the experimental verification was improved. Therefore if I am explaining the philosophy based on science, it means that the philosophy is more and more clear due to the advanced logic. I told you already that the logic (science) is only useful to refuse any item of creation as not God.
We should base the subject of philosophy related to God on good logic, which is scientific and systematic without defects like mutual contradiction, ad-infinitum etc.
The example for ad-infinitum is that an endless chain is created in statements like ‘which is the cause for God?’ In the analysis of creation, you may go on stating the cause for every cause.
You may say that the cause for earth is water. The cause for water is fire. The cause for fire is air. The cause for air is space. The cause for space is God (Atmana Aakashah… Veda). You should stop at a particular cause, which has no cause. If you go on giving cause to every cause, the chain will never end. Such a defect is called as ad-infinitum (Anavasthaa). To remove this defect, we have to stop at some cause, which is called as the ultimate cause i.e., the God. Hence, the subject of philosophy (Vedanta) should be always based on good logic (Sat tarka) only. Shankara told this point that bad crooked logic should be stopped and good logic should be followed in any discussion (Dustarkah suviramyataam shrutimatah tarkonu sandhiyataam…).