Musician, gardener, cynic, idealist: the shy Beatle we never really knew

George Harrison's musical career covered his life from the age of 15 to not far short of 59. What counts for most in quality of inspiration occupies an eight-year span between his first recorded song, "Don't Bother Me", in 1963 and the groundbreaking charity live album The Concert for Bangla Desh made at Madison Square Garden on 1 August 1971. After this short personal golden age, Harrison was for a while knocked sideways by the loss of his first wife, Patti, to his best friend Eric Clapton, while post-Beatles legal wrangles effectively kept him out of the recording studio for two years. His later work never scaled its previous heights and his sales dwindled accordingly.

Younger than both Lennon and McCartney, Harrison grew up faster than either. As a young man, he was laconic, sardonic and melancholic – qualities which ran life-lastingly deep in him and which inculcated a certain sourness detectable in the harmonies and chord-changes of many of his songs. What lay behind this sourness was the way life tasted to Harrison: bitter with disappointment in human nature and its indifference to the philosophical conun- drums posed by the mere fact of being alive. Harrison was born deeper than his mega-talented colleagues and felt more deeply – and more sadly – than they did. For him, as a youth, the world was a dark and lonely place.

Fortunately he had a famously dry wit with which to protect and entertain himself and his fellow Beatles. Still more fortunately, he soon discovered a palliative for his philosophical problems when, during February 1965, he came upon the teachings of Hindu religion while on location in the Bahamas for the film Help!. Being a man of unusual sincerity of conscience – upon which his sardonic humour was built – Harrison moved on to complete adulthood at the age of 22 when he encountered the Indian scriptures. From then on, he became the spiritual heart of the Beatles and the group's leader in exploring the transcendental impulses within their later work.

John Lennon, meanwhile, was off in acid wonderland, a delusory psychic locale from which Harrison quickly sought to escape. He sang about this in "It's All Too Much" from the soundtrack of Yellow Submarine. McCartney was fully occupied in holding on to the dream of the Beatles, or as Harrison soon came to see it, the delusory aspect of the image. This was at a time when events were conspiring prematurely to tear the group apart. Indeed, it was Harrison who first threatened to leave the band in August 1966, securing, in exchange for his assent to stay, a promise from Brian Epstein to call a halt to the group's touring career. He then immediately departed to India to study sitar with Ravi Shankar.

While Lennon quested ("Tomorrow Never Knows") or clowned ("You Know My Name Look Up the Number") and McCartney equivocated ("The Fool On the Hill"), Harrison arrived almost instantly at a resolution of his contrary aspects: the cynic and the idealist. Not being sentimental, he was ahead of his friends in realising that his charitable side needed to be given practical form as he grew up, a realisation he grasped through meditating on the Hindu law of karma: the ever-oscillating, yet resolvable, fortunes of the soul's burden of attachment to the material world. The law of karma reconciled Harrison's antithetical aspects: he could justify his cynicism in its religious form as fatalism and his loving side in the principle of compassion whereby the sentence of karma may be served out and escaped in time. His songs of 1965-70 are obsessively concerned with questions of delusion, time and love's law in action.

Meditation on the law of karma never entirely solved Harrison's philosophical problems. They remained a burden that was almost tangible in the weight of the wall-of-sound production which Phil Spector lavished on the artist's first solo album, All Things Must Pass, released in November 1970 and latterly seen as his masterpiece. The main problem was Harrison's dilemma in attempting to live a spiritual life in a material world – a world in which he found it hard to steer clear of drugs and alcohol, let alone the sad addiction to nicotine which eventually killed him. Further difficulties of conscience afflicted an essentially humble man who was willy-nilly a millionaire star – a man whose need for peace and privacy (and, after Lennon's assassination, shelter from a dangerous world) clashed with his spiritual belief in compassionate responsibility through engaged participation in earthly life.

Harrison saw that the Beatles were, in one way, a beautiful dream that everyone was having about the idealistic and optimistic era of the Sixties. His first instinct was to revolt against this on the grounds that since it was a sort of illusion, he should no longer contribute to it. When he saw that illusions are there to be transcended, he began to join in again on the basis that, since the dream of the Beatles was almost universally shared, he may as well attempt to make the Beatles' work more spiritual in its effects. "Within You Without You" is, in philosophical terms, the core track of Sgt Pepper's Lonely Hearts Club Band just as Harrison's beliefs were those of the entire group from around 1965 onwards.

George Harrison's struggle with the material world never ceased and he found himself living the life of a recluse in a gigantic country house with a huge garden, recording many songs about the conflict between the immortal soul and the life of money and possessions. He found much solace in gardening, an interest in the green world at one with the vegetative harmonic quality of Indian music in which melody unfolds like tendrils while remaining rooted in one tone. Despite his melancholy streak, Harrison was convinced of the presence of divinity in the cosmos, and his life was integrated in a way Lennon never had a chance to attain and which McCartney only slowly reached through his maturing relationship with his beloved wife Linda.

Among the more persuasive arguments for the existence of God is that we once had the Beatles, making their joyful noise. George Harrison is gone from Earth, but if he was right in his beliefs, he lives on in a newly vibrant dimension. Let's hope so.

Ian MacDonald is the author of 'Revolution in the Head – the Beatles' Records and the Sixties' (Pimlico, £8.99)