In 1509, Mr Luca Pacioli, a Franciscan friar, wrote a three-volume book called De Divina Proportione about the famous golden ratio. This is a theorem that connects the worlds of art and mathematics – in short, to set out a scientific rationale for beauty. But peruse the back catalogue of Pininfarina, the legendary Italian car design house and coachbuilder, and you can’t help thinking that Mr Pacioli had it wrong all along. At Pininfarina, sheer passion has always held sway over reason. In its heyday, the company’s skill in blending engineering and beauty was unmatched.

Pininfarina’s founder, Mr Battista Farina, was born in Cortanza d’Asti, near Turin, on 2 November 1893, the 10th of 11 children. This won him the family nickname Pinin – “youngest brother” in the ripe Piedmontese dialect. (In the early 1960s, a personal petition to the president of the Italian Republic enabled Mr Farina to change the family name to Pininfarina.)

His passion for cars and aerodynamics started early. Aged just 12, he began working at Stabilimenti Industriali Farina, the coachbuilding works owned by his brother, Mr Giovanni Farina. At 17, he submitted a design for a new Fiat, winning the approval of the company’s boss (and one of MR PORTER’s all-time style icons) Mr Giovanni Agnelli, who clearly recognised a precocious talent.

Following WWI, Mr Farina travelled to the US to see for himself the rapid strides the automotive industry was making. As if impressing Italy’s leading car manufacturer weren’t enough, in Detroit, a city that would later make him an honourary citizen, he met Mr Henry Ford. Mr Ford offered him a job, but Mr Farina declined, preferring to return home, where he immersed himself in the burgeoning motor-racing scene, with some success. By now, he was also married, and had two children: Gianna, born in 1922, and Sergio, born in 1926.

Four years later, Carrozzeria Pininfarina was established in Turin. It swiftly prospered as a body manufacturer and was noted for its adherence and understanding of aerodynamics, an emerging science in the 1930s, which lent its cars a swooping, futuristic flamboyance that was also highly functional. Mr Farina’s rapid rise was mirrored in the achievements of Alfa Romeo and Lancia, which flourished in this pre-war period. But Mr Farina also courted, and was courted by, US behemoth General Motors and French giant Renault.

Post-WWII, Pininfarina wasted little time in re-establishing itself. Indeed, two of the most important developments in the firm’s history occurred within five years. In 1947, the Mr Farina-designed Cisitalia 202 premiered at the prestigious Villa d’Este motor show, and then appeared at the Paris Salon de l’Automobile. Its aluminium frame was clothed in a handcrafted body of remarkable elegance and proportion, its lines flowing in a perfectly realised rhythm to culminate in a gracefully sculpted rear end that could stand comparison with Italy’s great masters.

The echoes of the Cisitalia 202 can be seen in countless cars that followed, its distinctive shoulder line reimagined by Pininfarina on Ferrari’s peerless 1960 250 GT SWB and 1961’s Aston Martin DB4 GT (whose body was the work of 23-year old novice Mr Ercole Spada at rival body maker Zagato). Although the complexity of its construction meant it was a commercial failure, the Cisitalia was selected for display in a 1951 exhibition in New York’s Museum of Modern Art. (It remains one of few cars to have had that honour.)

Mr Enzo Ferrari, among others, was clearly paying attention. Having started his own car company in 1947, Il Commendatore, as he was known, had flirted with most of Italy’s design houses, but decided that Pininfarina was the one he really wanted to work with. This gave rise to one of the car business’s most celebrated anecdotes. Mr Farina was too proud to travel to Mr Ferrari’s home in Modena, and Mr Ferrari, in turn, was too stubborn to meet Mr Farina in Turin. So these two soon-to-be giants of Italian design and engineering agreed to meet in the middle, in a restaurant in Tortona. Fortunately for car lovers the world over, the meeting was a success, although Mr Ferrari was rather taken aback when Mr Farina put his 25-year-old son, Mr Sergio Farina, in charge of this prestigious new contract.

Starting with the 212 Inter in 1952, Pininfarina went on to design hundreds of Ferraris over the next 60 years. It’s only in the past five years that the company has set up its own centro stile (design house), presided over by the great Mr Flavio Manzoni, although officially the partnership continues. Pininfarina clothed Ferrari’s magnificent chassis and power trains in a series of breathtaking bodies, most of which were fabricated by the gifted Modenese artisan Mr Sergio Scaglietti.

For students of design, the 1950s and 1960s represent the car industry’s most fertile period. It was an era in which designers were unencumbered by legislative demands and safety considerations. Bertone, Fantuzzi, Ghia and Vignale all worked wonders, yet Pininfarina was undoubtedly king. Alfa Romeo’s gorgeous Giulietta Spider, Lancia’s Aurelia B24 Spider and Flaminia Coupé, Maserati’s A6 GCS and Ferrari’s 250 PF Cabriolet and 375 MM – to name but two Prancing Horse models – are regarded as some of the most sublime motor cars ever made.

By now installed in a new factory in Grugliasco, tellingly, Pininfarina worked similar miracles with mainstream cars, including the Peugeot 404 and various British Motor Corporation (BMC) saloons, exporting a winning dose of la dolce vita to less-than-glamorous French and British provincial towns. Then there was Alfa Romeo’s Duetto Spider, the lissom little roadster immortalised in Mr Mike Nichols’ classic film The Graduate.

Mr Battista “Pinin” Farina handed the reins to his son and his son-in-law, Mr Renzo Carli, in 1961. He continued travelling, became a keen film-maker, was awarded the Légion d’Honneur in France and became an honourary member of the Royal Society of Arts in London. He died on 3 April 1966, but even now, on the 50th anniversary of his passing, he is cited as the single most influential car designer of all time. To put it another way, if the car was the defining invention of the 20th century, then Mr Battista Pininfarina was its Picasso.