Ramon Llull, around 1275, designs a method, which he will first publish in full in his Ars generalis ultima or Ars magna ("The Ultimate General Art", published in 1305), of combining religious and philosophical attributes selected from a number of lists.

It is intended as a debating tool for winning Muslims to the Christian faith through logic and reason.

Through his detailed analytical efforts, Llull has built an in-depth theological reference by which a reader could enter in an argument or question about the Christian faith.

The reader would then turn to the appropriate index and page to find the correct answer.

Llull also invents numerous 'machines' for the purpose.

One method is now called the Lullian Circle, each of which consists of two or more paper discs inscribed with alphabetical letters or symbols that refer to lists of attributes.

The discs can be rotated individually to generate a large number of combinations of ideas.

A number of terms, or symbols relating to those terms, are laid around the full circumference of the circle.

They are then repeated on an inner circle that can be rotated.

These combinations are said to show all possible truth about the subject of the circle.

Llull bases this on the notion that there are a limited number of basic, undeniable truths in all fields of knowledge, and that we can understand everything about these fields of knowledge by studying combinations of these elemental truths.

The method is an early attempt to use logical means to produce knowledge.

Llull hopes to show that Christian doctrines could be obtained artificially from a fixed set of preliminary ideas.

For example, one of the tables lists the attributes of God: goodness, greatness, eternity, power, wisdom, will, virtue, truth and glory.

Llull knows that all believers in the monotheistic religions—whether Jews, Muslims or Christians—would agree with these attributes, giving him a firm platform from which to argue.

The idea will be developed further by Giordano Bruno in the sixteenth century, and by Gottfried Leibniz in the seventeenth century for investigations into the philosophy of science.

Leibniz will give Llull's idea the name ars combinatoria, by which it is now often known.

Some computer scientists have adopted Llull as a sort of founding father, claiming that his system of logic was the beginning of information science.