 Man uses the spoken or written word to express the meaning of what he wants to convey. His language is full of symbols, but he also often employs signs or images that are not strictly descriptive. Some are mere abbreviations or strings of initials, such as UN, UNICEF, or UNESCO. Others are familiar trademarks, the names of patent medicines, badges, or insignia. Although these are meaningless in themselves, they have acquired a recognizable meaning through common usage or deliberate intent. Such things are not symbols, they are signs, and they do no more than denote the objects to which they are attached. What we call a symbol is a term, a name, or even a picture that may be familiar in daily life, yet that possesses specific connotations in addition to its conventional and obvious meaning. It implies something vague, unknown, or hidden from us. Many Cretan monuments, for instance, are marked with the design of the double ads. This is an object that we know, but we do not know its symbolic implications. For another example, take the case of the Indian, who, after a visit to England, told his friends at home that the English worship animals because he had found eagles, lions, and oxen in old churches. He was not aware, nor are many Christians, that these animals are symbols of the evangelists and are derived from the vision of Ezekiel, and that this in turn has an analogy to the Egyptian sun god Horus and his four sons. There are moreover such objects as the wheel and the cross that are known all over the world, yet that have a symbolic significance under certain conditions. Precisely what they symbolize is still a matter for controversial speculation. As a word or an image is symbolic, when it implies something more than its obvious and immediate meaning, it has a wider unconscious aspect that is never precisely defined or fully explained, nor can one hope to define or explain it. As the mind explores the symbol, it is led to ideas that lie beyond the grasp of reason. The wheel may lead our thoughts toward the concept of a divine sun, but at this point reason must admit its incompetence. Man is unable to define a divine being. When with all our intellectual limitations we call something divine, we have merely given it a name, which may be based on a creed, but never on factual evidence. Because there are innumerable things beyond the range of human understanding, we constantly use symbolic terms to represent concepts that we cannot define or fully comprehend. This is one reason why all religions employ symbolic language or images. But this conscious use of symbols is only one aspect of a psychological fact of great importance. Man also produces symbols unconsciously and spontaneously in the form of dreams.