You use fundamental to describe things, activities, and principles that are very important or essential. They affect the basic nature of other things or are the most important element upon which other things depend.
You use fundamental to describe something which exists at a deep and basic level, and is therefore likely to continue.
If one thing is fundamental to another, it is absolutely necessary to it, and the second thing cannot exist, succeed, or be imagined without it.
You can use fundamental to show that you are referring to what you consider to be the most important aspect of a situation, and that you are not concerned with less important details.
seminal
Seminal is used to describe things such as books, works, events, and experiences that have a great influence in a particular field.
lofty
A lofty ideal or ambition is noble, important, and admirable.
A lofty building or room is very high.
If you say that someone behaves in a lofty way, you are critical of them for behaving in a proud and rather unpleasant way, as if they think they are very important.