What is the sense that most stimulates spiritual impression? It probably differs from person to person. Some may best respond to sight with the beauty of a sunset at one end of the spectrum and some distortion of modern art at the other. Some to sound with a Bach prelude or piece of Renaissance polyphony set against the cacophony of rap. I would not argue with anyone who put forward either of these. But for me the sense of smell has the power to be the most spiritually evocative. The scents of certain flowers and plants can summon up the intimation of higher worlds like nothing else while I find the smell (and taste, closely linked, of course) of garlic very unpleasant. But then it has a high sulphur content and sulphur has long been associated with hell! It is interesting, however, to note that orthodox Brahmins do not eat garlic, believing it to stimulate the evil passions such as anger as well as sexual desire. Furthermore, the Buddha had this to say in the Surangama Sutra.
"Ananda, all beings live if they eat wholesome food and die if they take poison. In their search for Samadhi, they should abstain from eating five kinds of pungent roots (i.e. garlic, the three kinds of onions and leeks); if eaten cooked, they are aphrodisiac and if raw, they cause irritability. Although those who eat them may read the twelve divisions of the Mahayana canon, they drive away seers in the ten directions who abhor the bad odour, and attract hungry ghosts who lick their lips. They are always surrounded by ghosts, and their good fortune will fade away day by day to their own detriment. When these eaters of pungent roots practise Samadhi, none of the Bodhisattvas, seers and good spirits come to protect them, while the mighty king of demons takes advantage of the occasion to appear as a Buddha as if to teach them the Dharma, defaming and breaking the precepts and praising carnality, anger and stupidity; at their death, they will join his retinue, and at the end of their time in his realm, they will fall into the unintermittent hell."
If that's not enough to put you off garlic, I don't know what is.
However we would do well to see it in context. It was directed to celibate monks spending long hours in meditation. In that kind of life anything that stimulated the physical aspects of being would be regarded as detrimental. For us today there are surely other things that are much worse in terms of what we put into our bodies and minds. We have brought the means of spiritual obstruction to a high state of sophistication. That being said, there is still something about garlic that really does accentuate the material and eliminate the spiritual. Despite its health-giving properties, widely trumpeted by its acolytes, it is, in my opinion, an impure food from a spiritual perspective.
In English there are many words for smell, all having a slightly different nuance of meaning. Fragrance, scent, aroma, perfume, odour, stink, stench, and doubtless others I can't think of at the moment. This bears witness to the wide range of olfactory influences and effects, going from the heavenly to the hellish. I'm not sure that any of the four other senses can quite compete with that even if sight and hearing must be considered more important in that they open up a greater degree of experience. It is not hard to function normally without a sense of smell whereas to be blind or deaf is always a massive handicap. But, for me at least, certain smells have a quality that can evoke a world beyond this one more intensely than anything the other senses can offer.
Given that life follows similar patterns at different levels of its manifesting, it is interesting to speculate what the spiritual equivalents of the five senses might be. I don't mean such things as clairvoyance or clairaudience. Those are merely extensions of physical sight and hearing to a non-physical domain. I am thinking of how the counterparts of the senses might appear in the mind. For example, we have the word vision applied both to physical sight and intellectual perception. We also have foresight and insight. Taste can refer to the tongue or to artistic discrimination. Feeling is the physical sensation of touch but it is also an emotional thing. It is not so obvious what the spiritual counterparts to hearing and smell might be but could hearing relate to sensitivity to the Word of God and smell to a kind of discernment?
God has not left us without witnesses to his reality but the trouble is we are so used to them that we take them for granted and ignore the miracle of what they are. But just think for a moment how extraordinary the senses are. Imagine that you only had four and then woke up one day to find a fifth had appeared. What a magical new world it would open up. You would surely see it as indicating something much more profound about life and what it is than is offered by a materialistic metaphysics.
But now imagine how your experience will differ after physical death when you slough off the earthly body which is a wonderful vehicle while in this world but, being formed of physical matter, is also something that hinders, darkens and impedes spiritual consciousness. You are born anew. Everything is more intense, brighter, fresher, clearer, deeper. Layers of dirt and grease have been wiped off your senses. The feeling of always having to engage with life at one or several removes has gone. You are now completely in life with no barriers to experiencing it fully. The senses as we know them now will have been transfigured. At least, that will be the case for those who have not lived entirely through the senses while in this life.