Economics as a broad discipline is sometimes treated as a hard and quantitative physical science and sometimes as a human and social qualitative science.
The ongoing debate revolves around whether economics follows certain mathematical laws which can be discovered, or whether it revolves more around generalities and tendencies which can be explored but never proved for certain.
Corporate finance, as a subset of economics, tends to be framed very much as a hard, mathematical science.
Whereas accountancy is a mathematical record of what has already occurred in relation to the trade and ownership of a company, corporate finance is the process of matching necessary funding to trade and the allocation of ownership through investment.