His name is often mentioned alongside Luís Vaz de Camões, Manuel Maria Barbosa du Bocage, and Fernando Pessoa.

[3] As a child, he took French lessons under António Feliciano de Castilho, a leading figure of the Portuguese Romantic movement, who resided in Ponta Delgada.

On writing to his old headmaster, he said: Your excellency once put up with me at your Colégio do Pórtico when I was still ten years old, and I confess that I owe you much for your great patience, for the little French that I have known until this day.

[1] The important fact in my life during those years, and probably the most decisive one, was the sort of intellectual and moral revolution that took place within myself, as I left a poor child, pulled away from an almost patriarchal living of a remote province immersed in its placid historical slumber, towards the middle of the irrespective intellectual agitation of an urban center, where the newly found currents of the modern spirit would come more or less to recuperate.

As all my Catholic and traditional upbringing swept away instantly, I fell into a state of doubt and uncertainty, as ever the more pungent as I, a naturally religious spirit, had been born to believe placidly and obey without effort to an unknown rule.

If to this I add a burning imagination, with which Nature had blessed me in excess, the awakening of the loving passions known to early manhood, turbulence and petulance, the enthusiasms and discouragements of a meridional temperament, a lot of good faith and goodwill but a severe lack of patience and method, and the portrait of my qualities and defects with which I, at 18 years old, penetrated in the vast world of thought and poetry, shall be drawn.

[1] Following this controversy, Quental traveled, engaged in political and socialist agitation, and found his way through a series of disappointments, eventually embracing a mild form of pessimism.

In 1866, he went to live in Lisbon, where he experimented with proletarianism and worked as a typographer at the National Press, a job that he also continued in Paris (where he went to support the French workers), between January and February 1867.

In 1869, Quental founded the newspaper A República - Jornal da Democracia Portuguesa with Oliveira Martins, and in 1872, along with José Fontana, began to edit the magazine O Pensamento Social.

He moved to Oporto, Portugal in 1879, and in 1886 published arguably his best poetic work, Sonetos Completos, which included many passages considered autobiographical and symbolic .

To Carolina Michaelis de Vasconcelos, a friend, he wrote of his need to end his poetry and begin a philosophical phase in his writing, to develop and synthesize his philosophy.

According to the Encyclopædia Britannica Eleventh Edition:Antero [stood] at the head of modern Portuguese poetry after João de Deus.

He had learned much and half-learned more, which he was unable to assimilate, and his mind became a chaos of conflicting ideas, settling down into a condition of gloomy negation, save for the one conviction of the vanity of existence, which ultimately destroyed him.

An interesting collection of studies on the poet by the leading Portuguese writers appeared in a volume entitled Anthero de Quental.