The Doctrine of Signatures

Before the age of scientific validation, have you ever wondered how humans knew which herbs to use for specific ailments? The Doctrine of Signatures offers a compelling explanation. Signatures, the natural markings and forms of plants, have long guided healers in understanding their uses. This ancient and deeply philosophical practice, finds resonance in the way plants reveal their medicinal purposes through physical characteristics. These plant signatures reflect the symbiotic relationship between human beings and the natural world, where form, colour and essence serve as intuitive guides to the medicinal properties hidden within Nature's pharmacy.

The language of plants

Throughout human history, the understanding of plants as medicine has not solely been a result of trial and error, but also through an intuitive, almost mystical connection with Nature. Ancient peoples observed the natural world with heightened awareness, noticing how the shapes, colours and growth patterns of plants often mirrored certain human organs or conditions. This gave rise to the understanding that plants held intrinsic signs or “signatures”, indicating their healing properties. These observations were not random, but guided by a deep instinct and spiritual attunement to the natural environment. Thus, the early knowledge of plant medicine often came from an innate sense of harmony between the human body and the earth, a wisdom that transcended mere experimentation and became foundational to many healing traditions. This connection eventually crystallised into the “Doctrine of Signatures”, a guiding principle that showed how the design of the plant itself could reveal its medicinal potential.

“All plants are our brothers and sisters. They talk to us and if we listen, we can hear them.” Arapaho proverb

The wisdom of Folklore

Indigenous peoples rightfully said that they were taught healing by the plants themselves. Among the Iroquois Indians, it was explained that if a person becomes ill and needs a plant for healing, the right plant would stand up and call the attention of the person to find it. The belief that the human body mirrors the world around it, a microcosm within the macrocosm, dates back to ancient traditions as old as humanity itself. Primitive cultures across the globe developed the art of understanding a plant's healing potential by observing its outward appearance and its relationship to the natural environment. Immersed in nature and under open skies, these early herbalists learned to interpret the language of plants by studying their unique adaptations and how they thrived under various conditions. This often involved observing animals, who instinctively knew which plants to seek out for their own healing. Through this deep connection to their surroundings, humans effectively unlocked the hidden wisdom within plant life, using it to heal and sustain their communities.

“Every blade of grass has its angel that bends over it and whispers, “grow, grow.” The Talmud

Wisdom through sensing not thinking

The wisdom of herbal folklore was acquired by sensing not thinking; experiential use of the whole panoply of sensory perceptions to acquire intimate plant knowledge. This meant picking parts of plants, nibbling on grasses, smelling flowers, chewing roots, rubbing leaves, feeling their textures between fingers, tasting the bitterness or sweet. Random and purposeful tossing plants onto the fire to imbibe their fumes, steeping their water in plants to explore different effects and adding others to food to enhance flavour. The sacred meanings given to plants have been handed down from generation to generation, through religions and nations and accordingly, one plant may have acquired many names or a single name may have been adopted for many plants. Universally, the plant held within itself its own wisdom to be discovered and utilised by humans.

The language of plants

By the late middle ages all of these ancient folkloric principles of human direct experience with plants were organised into a major record of plant therapeutic properties called the “Doctrine of Signatures”. The Doctrine was based on the ancient idea that a plant resembles the disease, organ or person for which it is remedial; this is the “law of correspondence.” Signatures in plants represent patterns of energy or archetypes and these correspond to similar patterns in people.

The value of many medicinal plants administered in Europe was determined by this categorisation, which taught that the healing herbs were signposted by God in some way for human’s guidance. In the West the concept behind the doctrine was first mentioned in the writings of Pliny the Elder, the brilliant Roman naturalist. The concept was later developed by Paracelsus (1490-1541), the Swiss alchemist who built on the widespread folk wisdom. This approach, though confronting to logical science proved to be surprisingly apt; science itself later validated that the actives present in these plants were medically appropriate for different ailments. This was herbal wisdom based on the direct experience of Nature, which at the time did not need science for proof of its value.

“Every herb has been brought into shape that is akin to its inner nature (by God)” Paracelsus

Reading the signs

“What is it that makes it so hard to determine whither we will walk? I believe that there is a subtle magnetism in Nature, which if we unconsciously yield to it, will direct us aright.” Henry Thoreau

Signatures provide the foundation of an intuitive approach to knowledge, a philosophy rooted in Plato and later embraced by Aristotle. Aristotle taught that formal logic originates from the eidos, meaning essence, primal form, or archetype. The signatures of plants were perceptible traits, observed by the senses and imbued with meaning by the mind. Some fascinating examples illustrate this ancient wisdom: Scophularia roots resemble swollen glands and were used to treat them, including haemorrhoids. Chelidonium’s orange sap, reminiscent of bile, indicates its ability to promote bile flow. Agrimonia, with its bristling tension, was used to ease nervous tension. Lungwort, fleshy and lung- like in appearance, was a trusted remedy for pulmonary diseases. Peony buds, resembling craniums, have been used since Galen’s time for brain health and epilepsy. Alkanet’s seeds, shaped like vipers, were employed to treat venomous bites. In Milton’s Paradise Lost (1667), the Archangel Michael uses the eyebright flower to cure Adam’s eye infection. Similarly, the Cherokee recognised purslane, with its worm-like appearance, as an effective treatment for intestinal parasites due to its gastro-protective properties.

“The soul does not perceive the external or internal physical construction of herbs and roots, but it intuitively perceives at once their Signatum.” “Thou shallst know all the internal, by looking at the outside.” Paracelsus

Skilful and unbiased observation of Nature

The concept behind the Doctrine of signatures teaches us to look for a sign in a plant that describes its medicinal properties in a very unscientific way. This process by no means diminishes it value, but helps us to see plants more deeply in their entirety to hear their message. We learn how two different objects or life forms resonate with each other if they share the same intrinsic character or essence. Paracelsus claimed that the plant would “look like what it cures”, whereas Samuel Hahnemann developed the science of homeopathy where “like cures like; he also interpreted the law of similar to mean, “It causes what it cures.” Plants help us discover unity as a dynamic quality revealing itself in the diversity of phenomena. We learn to see connections that at first may appear to be separate from each other.

“What the eyes perceive in herbs, stones or trees is not yet a remedy, the eyes only see dross.” Paracelsus

Steiner's Approach

Rudolf Steiner developed an entire system of holistic medicine based on the laws of correspondence and the Doctrine of signatures. He recommended the use of mistletoe extract as a cure for cancer. Mistletoe grows as a tumour-like parasite on its host tree and even the different varieties of host trees denoted the different types of cancers. Fifty years after his death, scientific research validated that mistletoe contains a peptide that punctures cancer cells and kills them upon contact. Steiner adopted Goethe's approach of analysing the plant or organism through its stages of development, this included its affinities to the old gods or planetary emblems, which were used, age after age, not only to express belief in the gods necessarily, but as symbols or archetypes of different powers.

“The expert must know how to recognise the virtue of all things by the signs, be it a herb, a tree, a living being or an inanimate object” Paracelsus

Well-known herbs that align with the doctrine of signatures:

Walnut: With its brain-like shape, the walnut has been associated with enhancing cognitive function and brain health.

Ginger: Its knobby, human-like form suggests its use in warming and stimulating circulation, particularly for cold extremities and digestive discomfort.

Ginseng: Often resembling the shape of a human body, ginseng has been used as a tonic for overall vitality, enhancing energy, longevity, and balance throughout the body.

Hawthorn: The red berries of hawthorn, similar in color to blood, indicate its affinity for the heart and cardiovascular system, long used to strengthen the heart and improve circulation.

St. John’s Wort: When crushed, this herb releases a red oil, symbolizing its ability to heal wounds and uplift the spirit, specifically in treating depression and nerve pain.

Turmeric: Its vibrant yellow colour aligns with the liver and digestive system, used to support detoxification and reduce inflammation, particularly in cases of jaundice or liver ailments.

Celery: The stalk’s hollow, jointed structure resembles bones, aligning with its use to strengthen and support bone health, being high in silicon, which is necessary for bone strength.

Garlic: Its layered bulbs, resembling an onion-like shield, signify its protective qualities, particularly its ability to ward off infections and harmful pathogens.

We too can read the signs

In our own gardens, the ancient wisdom of plant signatures is still alive, ready to be rediscovered. By observing herbs with mindful curiosity, we can begin to see how their shapes, colours and scents reveal their healing potential. When we combine this with our daily meditation, our spiritual dip into the ocean of Cosmic Consciousness, we heighten our awareness and attune to the subtle energies of Nature. In this state of deeper presence, plants speak to us, showing how they can nourish, heal and protect us. Through this intuitive connection, a whole new world of healing opens up, where the wisdom of the natural world unfolds in perfect harmony with our own.