Many highly intelligent men will naturally gravitate towards logic due to their ability to rapidly process and dissect information, discern patterns, and understand intentions. They will often rely on this intellectual strength heavily, believing themselves to be akin to quantum computers of logical exploration.
As they progress in life, they will come to realise that when they reject their gut instincts in favour of pure logic, logic does not always prevail - an unsettling revelation of the limits of reason, one that often remains wilfully buried. This marks the gradual build-up towards the discovery and formation of their own spiritual concept - regardless of whether or not it is grounded in religion. Unless a life-altering event, major achievement, or profound heartbreak occurs - leading to a spiritual awakening, this shift or "correction" towards spirituality often emerges in their 30s. Around this time, they begin to reflect on past experiences that have defied explanation and grow weary of analysing basic patterns. Their soul beckons them towards that which cannot be easily unravelled. They come to realise that no logical system alone can capture the full complexity of human experience or provide all the answers. Thus, they begin to craft their own robust spiritual manifesto - one in which no stone is left unturned - something they build, reflect upon, and carefully refine.
The more intelligent and rational a person is, the more they demand a spirituality that makes sense - where it feels more logical to believe than to not - not in the sense of being provable, but in the sense of being necessary to acquire deeper understanding and meaning. The process of spiritual ascension often brings about a series of profound realisations, major shifts in their worldview, and a newfound ability to synthesise even greater mind-blowing revelations. Through this, they realise that their spirituality, or the belief in something greater, benefits them holistically. It is the "missing piece" that unites the scattered fragments of awareness within their mind. In many ways, it softens their souls, yet by doing so, it strengthens their spirit, making a fulfilling life more accessible.
I agree in a sense that logic has limits - but even the latter tendency you explain, to become more spiritual and look at things holistically still requires rationality. Otherwise you end up believing woohoo nonsense that conflicts with reality.
Logic is a formalised and somewhat rigid application of rationality. Just like a mathematical formula, it can describe reality accurately within a limited defined context, but if the context changes and you continue to rigidly apply the same formula, it can lead you astray. Often the evidence imparted by the reality we deal with everyday gives us a sense of where truth lies, without being able to reduce it to a logical formula - at least not yet. This is essentially what’s called intuition. So yes, formal logic has limits, but staying rational and connected to reality as best we can remains crucial.