The first tool that a child knows how to use is his own senses. Even before a baby is born, he is able to hear the voice of his mother when she speaks and when he arrives to our world; he knows when she is in the same room because he is able to recognize familiar smells (Lois Barclay Murphy and Rachel Moon, Zero to Three Journal: “Babies and Their Senses”).

As he grows up, he gradually develops and refines his senses to progressively learn more about the world around him. Understanding the importance of the senses to the child’s learning, Maria Montessori has always believed that a child observes the world around him best through his senses and that teachers should encourage children’s observation by offering them activities from which they learn by using their senses (Maria Montessori (1988), The Discovery of the Child).

“The senses, being explorers of the world, open the way to knowledge. Our apparatus for educating the senses offers the child a key to guide his explorations of the world’ 
(Maria Montessori (1988), The Absorbent Mind, Oxford: Clio Press).

“The training of the senses, insofar as it makes a man an observer, not only fulfills the generic function of adapting him to the contemporary mode of civilization, but it also prepares him for the exigencies of life” (Maria Montessori (1988), The Discovery of the Child).

2.The Senses as Key to the Universe

Whenever an object is given to a child, he learns about it by holding it with his hands, shaking it, putting it in his mouth, smelling it and looking at it from all sides. For adults, this might seem unnecessary or consider the child only playing with the object but in fact, this is exactly the right way to get to know a new object for any object has nine properties: Shape, Color, Texture, Sound, Smell, Taste, Temperature, Weight and Size. Using his senses, a child gets to know an object by learning those properties.

The Montessori sensorial materials help children identify the properties of objects by triggering the child’s senses in an activity to learn about a certain quality while isolating other qualities. When the child masters this activity, he then becomes able to make connections between the quality he learned in this activity and the environment that surrounds him (Maria Montessori (1967), The Montessori Method).

This can be understood from an example stated by a Montessori teacher from New Zealand, Janet Du Fall (Montessori.org.nz/Montessori-Quotes):

“I observed a young boy, not yet three years old, feeling the rough and smooth board some days after I had presented it to him. As he ran his fingertips across the surface he said, ‘Me smooth, Campbell smooth, Mummy smooth, Daddy rough.’ He was expressing his understanding of the connection between the stimuli from the touch board to the sensation of the skin texture of his family.”

Maria Montessori also stressed on the fact that adults in different fields are in need of strong senses in order to excel in their jobs. For example, a cook should have a strong sense of smell in order to be able to identify, let’s say, fresh fish. Also, a physician theoretically studies the pulses but if he were not able to feel the pulse sensation with his fingers then his studies would be in vain. Same idea goes with his ability to hear the heartbeats and so on. She believed that if people did not perfect their senses when they were children, it is almost impossible for them to do so in their adulthood (Maria Montessori (1967), The Montessori Method).

3.Montessori Sensorial Training Materials

Since Maria Montessori encouraged the development of the child’s senses, therefore in the sensorial training, materials were designed to stimulate the child’s senses to learn about properties of the objects around him. The sensorial materials focus on the child’s five senses; visual sense, tactile sense, olfactory sense, gustatory sense, and auditory sense. In fact, there are even special senses that were triggered in the Montessori materials such as the baric sense (sense of weight), thermic sense (sense of temperature) and the stereognostic sense (sense of identifying the shape and size of an object by only holding it with the hands).

Through the visual sense, a person discriminates between color, size and form. The pink tower for example, which is the second activity presented to the child in the sensorial training, after the knobbed cylinders, consists of 10 blocks of the same shape (cube) and the same color (pink) but different sizes so that when the child builds them on top of each other, they form a tower. The color and form properties are isolated in order for the child to refine his ability to differentiate between different sizes. In color boxes 1 and 2 activities, the child uses his visual sense to learn about colors and to match the same colors together. This activity is also important for the teacher to determine in case a child suffers color blindness.

Like all materials in the sensorial training, the concept of isolation is applied where the color tablets have the same shape and size but of course, different colors to make sure the child’s attention is dedicated to learning about the colors. In color box 3, the child refines his visual sense not only in a way in which he is enabled to differentiate between different colors but to even grade different shades of each color. As for an example of an activity that introduces different forms, there is the geometric cabinet, which not only introduces different forms such as triangles, circles, and squares but it also enables the child to differentiate between different sizes of each shape and different ways in which they exist. For example, a triangle may be isosceles or scalene and there exists four sided forms other than a square but they have different inner angles such as a trapezium or a parallelogram, and so on. The child learns about all those geometric forms through his visual sense as well as his muscular memory as he feels each shape with his hands.

The sound cylinders are an activity that refines the auditory sense by introducing the child to different sounds and then matching similar sounds together. It consists of cylinders that contains different components that the child cannot see through the cylinders, for example, rice, sand, beans, etc. The idea is that when a child shakes a cylinder next to his ears, it makes a certain sound and of course different components make different sounds as they shake.

The olfactory sense is refined through an activity that is called “Smelling jars” same like the sound cylinders; each jar is filled with a different component that the child cannot see. This time the component should have a certain smell, for example mint or banana. The child learns how to smell each jar and also matches jars that have the same smell together.

Like the sound cylinders and the smelling jars, the tasting jars or bottles contain different components that the child cannot see. Most importantly, each component having a certain flavor so that the sense of taste of the child is refined. The child is introduced to each flavor and then matches jars that have the same flavor together.

The touch boards are an activity that refines the tactile sense of the child by introducing different surfaces to him and learning that some surfaces can be smooth and others are rough. Also, at some point, the child learns that there are different grades of roughness and different grades of smoothness.

The baric sense or sense of weight of the child is developed in the baric tablets activity as he is first introduced to a heavy tablet and a light tablet and then he holds some tablets and determines whether each one is considered light or heavy. At some point, the child’s baric sense if further refined when he is then introduced to a medium weight so that he is able to then to determine whether a tablet is heavy, light or medium.

The thermic sense or sense of temperature of the child is refined when he is introduced to the thermic bottles which contains different temperatures of water.

Finally, the stereognostic sense is developed through the stereognostic bags where the child holds an object inside a bag (without seeing it) and learns about its shape through his hands and then at some point, he takes it out and then brings out its match from the bag without looking at all. In the mystery bag, the child’s stereognostic sense is also refined through holding an object inside the bag and naming what it is without seeing it.