Square – I’ll clarify. The methods of many geonim and rishonim, including rav saadia, rambam, rabbeinu bachya, and several others, included using philosophical arguments to prove the existence of Hashem and vital notions of Him, including oneness, incorporeality, omniscience, shlaimus, that He is a boreh umanhig (this was in sharp contrast to the philosophers of their time and the Greeks), and that Hashem created the world yash may’ayin.
They held that such study – when undertaken after amassing Torah knowledge and the stripping of bias and bad middos that comes in its wake – is a kiyum of the mitzvah of ve’hashayvosa, that you shall place emunah in your heart. If done without the strong background in shas and poskim, this is extremely dangerous, as one can come to disbelief or doubts. The rambam cautions would-be philosophers that such pretentious prattling “destroys the world” in his words, since sometimes the free thinker (or academic) will accept torah misinai, sometimes he won’t. Sometimes he’ll believe in Hashem, other times the alternative will appear clear to him. These are verbatim translations of the words of the rambam, whose name is dragged in the dirt by people who never excelled in gemara and real learning, and instead chose to become self styled “philosophers” who devote their time and energy to “machshava”. Modern Orthodoxy is full of such mischievous peddlers of false sophistry, who spend time wondering why people are important and if they’re the purpose of creation, while ignoring true learning that is mayviah lidai maysoh, that leads to fulfilling the mitzvos, yiras shomayim, tikun hamidos, and ahavas Hashem.
Then there’s havchanah. That is recognition of Hashem both in our lives, as well as in the briah. The rambam says that studying nature (not secular biology courses where the intent is to hide the Creator) brings one to ahavas Hashem. The chovos halevavos devotes an entire shaar, called shaar habechina, to this study. Rav avigdor miller, the chazon ish, and virtually every achron writes about this, even the most anti-philosophy shitos. There is no harm in this study, as it does not involve reckoning with the “other side”, as attemps at philosophical proof does.